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The (1-x)Ba 0.94 Ce 0.04 TiO 3 -xBi(In 1/2 (Li 0.5 Ta 0.5) 1/2)O 3 (BCT-BILT) relaxor ferroelectric ceramic system was explored based on the A-site vacancy design and defect dipole engineering. The impacts of different doping concentrations on the phase composition, dielectric and energy storage performance of the BCT-BILT ceramics were studied and discussed in detail. The pure BCT and 0.95BCT-0.05BILT samples exhibited a mixed crystal structure of tetragonal (T) and pseudo-cubic (PC) phase, while the BCT-BILT samples with x > 0.05 possessed a cubic (C) phase, accompanied by the secondary phases of BaBi 2 Ta 2 O 9 and BaTa 2 O 6. With an increase in the BILT doping concentration, the surface morphologies of the ceramics were continuously modulated, and the dielectric loss had been reduced to 0.001 at 1 kHz, which was beneficial to improve the energy storage properties. Compared to the pure BCT, the breakdown field strength was significantly enhanced owing to the formation of Aurivillius phase BaBi 2 Ta 2 O 9 and the increased dielectric relaxation. Ultimately, the highest energy storage density of W rec = 0.7 J/cm3 and high energy conversion efficiency of η = 95 % was realized at the composition of x = 0.05 under a small electric field of 130 kV/cm. Furthermore, the good temperature stability with the Δ W rec / W rec30°C < 9 % and Δ η / η 30°C < 6.5 % was acquired for the samples with x = 0.20–0.30 in the temperature range of 30–120 °C, owing to the synergistic roles of the defect dipoles, impurities BaBi 2 Ta 2 O 9 , and polar nanoregions (PNRs). The 0.95BCT-0.05BILT ceramic obtains discharge energy density W dis of 0.35 J/cm3 and fast discharge speed t 0.9 of 312 ns at 60 kV/cm, current density C D of 255.4 A/cm2 and power density P D of 10.2 MW/cm3 at 80 kV/cm. This work is of guiding significance for designing and optimizing energy storage performance of lead-free relaxors from the perspective of defect building and engineering. [ABSTRACT FROM AUTHOR]

In mixed crystals, two or more elements exhibit comparable properties and can be substituted freely. As a special type of "substitutional doping," the properties of materials can be adjusted by altering the doping ratio of elements. Mixed-vanadate crystal Lu x Gd 1-x VO 4 is a promising laser host material with excellent chemical stability, mechanical property and thermal conductivity. The substitutional doping ratio of the two rare-earth elements determines the value of x. The thermal, optical, and laser properties of the material vary with x. However, the two types of atoms showing little difference in the same location in mixed crystals form substitutional solid solutions with alike atomic radii as well as electronic structures. Therefore, distinguishing comparable elements in mixed crystals at the atomic scale and quantitatively analyzing the doping ratio in mixed crystals are challenging. In this study, combining high-angle annular dark field (HAADF) and electron energy-loss spectroscopy (EELS), we accurately characterize the atomic structure of mixed-vanadate single crystal Lu x Gd 1-x VO 4 along the [111] orientation as well as the distribution of two rare-earth elements at the atomic scale. The ratio of Lu and Gd and the doping rules in the crystals are quantitatively analyzed. In addition, combined with the energy dispersive X-ray spectroscopy (EDS) results of the [100] crystal orientation, a uniform random distribution of Lu and Gd in the Lu x Gd 1-x VO 4 crystal is confirmed. This study provides a new means of understanding mixed-crystal structures and solves the problem of quantitative analysis of elemental doping in materials at the atomic scale, thus laying the foundation for exploring the relationships among composition, structure, and function in materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Perfluoride glass ceramics (FGCs) with SrF 2 /CaF 2 mixed crystals were prepared using a concurrent rapid-quenching-crystallization process. The FGCs contained dense, homogeneous, round crystals of sizes less than 1 μm with high transmittance (exceeding 80 % at 3–8 μm) and low phonon energy (508 cm−1). The fluorescence properties of the FGCs doped with Er and Dy were investigated. The energy transfer efficiency between Er and Dy reached 93.81 % and 98.13 %, corresponding to Er: 4I 11/2 to Dy: 6H 5/2 and Er: 4I 13/2 to Dy: 6H 11/2 , respectively. This enhancement is attributed to the enrichment of rare-earth ions in the crystals induced by phase-separation and low phonon energy of the host material, FGC. Moreover, the average lifetime of Er: 4I 11/2 in FGC reached 10.13 ms, which is the highest reported value for glass ceramics to our knowledge. This study enriches the research theory of FGC and provides guidance for expanding the properties of materials for mid-infrared photonics. [ABSTRACT FROM AUTHOR]

The advantage of a complex catalyst in which several catalysts are mixed is that the overall reaction rate can be efficiently increased by increasing each sub-reaction rate. Each constituent catalyst in the complex catalyst must be as well-mixed as possible—while maintaining high catalytic activity—owing to the short reaction time of these sub-reactions. This study reports a facile synthetic method to mix two catalysts homogeneously at the nanoscale while keeping their crystal structure intact. ZnNiCu hydroxide nanoplates with a mixed crystal structure composed of ZnNi and ZnCu hydroxides, which could promote H 2 O dissociative adsorption and H 2 desorption, respectively, were synthesized by a simple cation exchange of ZnO nanoparticles and a precursor mixture of Ni and Cu. ZnNi and ZnCu hydroxides in the nanoplates were mixed at the nanoscale while maintaining their respective crystal structures; density functional theory calculations show that these structures could effectively perform H 2 O dissociative adsorption and H 2 desorption, respectively, resulting in high activity in the overall photocatalytic hydrogen evolution reaction. ZnNiCu hydroxide composites were prepared, and photocatalyst H 2 productivity was predicted through DFT calculations. The well-mixed structure of ZnNi and ZnCu hydroxides at the nanoscale with keeping their crystal structures plays key role in maintaining fast reaction rates of both H 2 O dissociative adsorption (ZnNi hydroxide) and H 2 desorption (ZnCu hydroxide). [Display omitted] • Synthesis of ZiNiCu hydroxide (ZNC) nanoplates by cation exchange. • Enhanced photocatalytic H 2 production caused by ZnNi/ZnCu mixture hydroxide structure. • Investigation of enhanced H 2 production through experiment and DFT calculation. [ABSTRACT FROM AUTHOR]

The hydrogen evolution reaction (HER) electrocatalytic activities normalized to electrochemically active surface area (ECSA) were systematically evaluated and correlated with its composition (i.e., Mo content up to 26 at. %), crystal structure (i.e., face-centered cubic (fcc) to orthorhombic phase and the mixed phases with different phase ratios), and crystallinity. The electrodeposited with mixed phases exhibited highest ECSA (up to 228 cm2 per 1 cm2 geometric surface area) compared to deposits with single phase, which serves as the dominant factor to enhance exchange current density and overpotential. Low overpotentials per ECSA were observed with Mo content of 5.16 at% (fcc) and 24.1 at% (mixed phases). After normalizing with ESCA, The Tafel slope and exchange current density were indifference with Mo content, crystal phase, and grain size. The metallic Ni–Mo thin films have low mixed potential and overpotential at 10 mA/cm2 of 20 mV and 120 mV, respectively. • Ni–Mo with different composition, and crystal structure were electrodeposited. • Mixed crystal phases resulted in highest electrochemically active surface area. • Mixed phases Ni–Mo electrodeposits also show to enhance exchange current density. [ABSTRACT FROM AUTHOR]

• The separation of aluminum by alkaline leaching of the intermediate oxide of nickel extraction from laterite nickel ore at 160 °C was studied. • The enrichment of scandium, a rare metal with high value, is realized. • The acid leaching behavior of alkaline leaching residue was studied by Eh-pH diagrams at 100 °C. • A closed-loop process was proposed for treating laterite nickel ore. As the demand for nickel increases sharply, it is of great significance to extract valuable metals such as nickel and cobalt from lateritic nickel ore with huge reserves. Based on the nitric acid pressure leaching process (NAPL) of laterite nickel ore, a clean process of laterite nickel ore treatment is proposed. The process includes concentration and crystallization of pressure leaching solution of nitric acid, pyrolysis of mixed nitrate crystal, alkaline leaching of mixed oxides and acid leaching of alkaline leaching residue. Based on previous work, the high-pressure alkaline leaching process of pyrolysis products (mixed oxides) and atmospheric pressure sulfuric acid leaching process of alkaline leaching residue were studied in this paper. First, the Eh-pH diagrams of metal-water system of common elements in laterite nickel ore was summarized according to the reaction equations of different substances in aqueous solution, and the subsequent wet leaching process was guided. The following alkaline leaching experiments showed that under the conditions of 300 g/L NaOH concentration, 3.5 mL/g liquid–solid ratio, 160 °C leaching temperature and 1 h leaching temperature, 85.0 % of aluminum in mixed oxides can be leached and scandium can be enriched by 13 times. Finally, under the conditions of initial sulfuric acid concentration of 4 M, temperature of 100 °C, leaching time of 30 min and liquid–solid ratio of 4 mL/g, the leaching rates of Al, Ni, Mg, Co, Mn, Fe and Sc in alkaline leaching residue were 92.0 %, 97.5 %, 98.4 %, 92.3 %, 62.7 % and 68, respectively. A new procedure for treating lateritic nickel ore is proposed, allowing for thorough recovery and usage of important components. The technique is green and environmentally benign, resulting in closed-loop production of laterite-nickel ore treatment with numerous application possibilities. [ABSTRACT FROM AUTHOR]

The ZnO/ZrO 2 binary catalyst system has been an emerging and promising catalyst for efficient production of H 2 through methanol steam reforming (MSR). Herein, ZrO 2 supports with different crystalline phases were prepared by the oxygen vacancy engineering strategy of Li doping, and then ZnO/ZrO 2 catalysts were prepared by the isovolumic impregnation method. The different quantities of doped Li have been found to have a significant impact on dominant crystal phase of ZrO 2 supports, which dictates the interaction between ZnO and ZrO 2 and the number of oxygen vacancies. In comparison with ZnO/ZrO 2 -20Li and ZnO/ZrO 2 -40Li catalysts with predominate tetragonal and monoclinic crystal phase, ZnO/ZrO 2 -3Li with a mixed crystalline phase exhibits higher catalytic activity for methanol conversion (X CH 3 OH) and CO selectivity (S CO). Complete methanol conversion of the best performing ZnO/ZrO 2 -3Li catalyst was observed at a very low CO selectivity of 3.1 % at 375 ℃. The XRD, UV, and XPS characterization results indicate that the strong interaction between ZrO 2 and ZnO leads to the appearance of large amount of oxygen vacancies at the ZnO/ZrO 2 interface, which greatly improves the performance of the catalyst. ZnO/ZrO 2 catalyst showed remarkable stability without obvious deactivation after 32 hours of continuous testing. This work highlights the effectiveness of oxygen vacancy engineering of the ZnO/ZrO 2 catalysts for applications in methanol steam reforming and other heterogeneous catalytic systems. [Display omitted] • The strategy of Li doping is used to alter the crystal phase of ZrO 2. • ZnO/ZrO 2 catalyst exhibits good activity with appropriate amount of Li doping. • The catalyst with mixed crystal phase of ZrO 2 has abundant oxygen vacancies. • The interaction between ZnO and ZrO 2 boosts the reactivity of MSR reaction. [ABSTRACT FROM AUTHOR]

Based on the effective mass approximation and the compact density matrix theory, the electronic states and optical absorption properties of intersubband transitions between the conduction-band energy levels in zinc blende InGaN/GaN/InGaN/GaN core-shell quantum dots (CSQDs) are investigated by using the finite difference method. The effects of hydrogen-like impurity and In component on the wave functions, transition energies, and optical absorption properties are discussed in detail. The results show that hydrogen-like impurity can cause the peak positions of optical absorption coefficients (OACs) and refractive index changes (RICs) to move to high energy area, and the peak values of OACs rise. Increasing In component of InGaN crystal in the core region of a CSQD has the same effect. But an opposite tendency will be found when increasing In component in the shell-well of a CSQD, i.e. optical absorption peaks move to low energy area and their values decrease. Comparing to the shell-well, the core region has more powerful confinement effect on electrons. So the better absorption properties are more likely to be obtained for this type of multi-layer InGaN/GaN CSQDs when In component in the core is larger than that in the shell-well. • The intersubband optical absorption coefficient and refractive index changes are studied in the InGaN/GaN CSQDs. • The hydrogen-like impurity is proved to be helpful for improving the optical absorption properties in these CSQDs. • The ternary mixed crystal effect on the optical absorption properties are analyzed in detail. [ABSTRACT FROM AUTHOR]

Here we present the study of spectral and kinetic characteristics of Tm3+ and Ho3+ ions system in LiY 0.3 Lu 0.7 F 4 mixed crystal. Polarized spectra of absorption and luminescence transitions between 3F 4 – 3H 6 and 5I 7 – 5I 8 states of Tm3+ and Ho3+ ions respectively as well as energy transfer efficiency were investigated. It was shown that LiY 0.3 Lu 0.7 F 4 mixed crystal provides some broadening of Tm3+ and Ho3+ spectral lines for 4f-4f intermultiplet transitions. The evaluated Förster energy transfer critical radius for LiY 0.3 Lu 0.7 F 4 : Tm3++Ho3+ (10 at. % + 2 at. %) crystal was 22 Å. The backtransfer efficiency from Ho3+ to Tm3+ in the described energy transfer process C Ho-Tm results in value of 0.83 × 10−40 cm6/s and relation of froward and back-transfer coefficients C Tm-Ho /C Ho-Tm appears to be 6.8 calculated from our spectroscopic data, which make it prospective active medium for sensitized laser oscillation in IR spectral region. • The absorption and emission spectra of the LiY 0,3 Lu 0,7 F 4 : Tm3+ + Ho3+ are shown for the first time. • Observed some broadening of Tm and Ho spectral lines for multiplet-to-multiplet transitions in mixed crystal LiY 0.3 Lu 0.7 F 4. • The evaluated Forster critical radius for LiY 0.3 Lu 0.7 F 4 was 22Å, which is a bit larger compared to previous results for LiYF 4 matrix. • The backtransfer efficiency from Ho to Tm takes value of 0.83 × 10−40 cm6/s, which is lower than values from previous results. [ABSTRACT FROM AUTHOR]

Sodium guanidinium bis(4-methylbenzenesulfonate) hydrate (NGMBS) crystallized in the monoclinic crystal system with non-centrosymmetric space group P2 1. The mixed ionic crystal assembly was stabilized by N H⋯O hydrogen bonding involving guanidinium ion and with Na+ ions surrounded by aqua ligands and S – O oxygen atoms completing six coordination involving with coordinate covalent and ion–dipole interactions. A supramolecular assembly in two dimensions (along the a and b-axis) is possible by H-bonding which brought the Na+ within a distance of 3.6493 Å. The two 4-methylbenzenesulfonate ligands in one formula unit were not identical and exhibited structural variations. Hirshfeld analyses indicated significant interaction due to N⋯H, O⋯H, and Na+ ... O. The vibrational bands were ascertained using FTIR. A cut-off wavelength of 273 nm and bandgap of 4.50 eV were estimated from UV–visible spectroscopy. The compound excited at 260 showed emission at 291 nm. Colour purity up to 95.62 % was estimated from chromaticity calculations. Kurtz-Perry's method confirmed that NGMBS showed NLO properties 1.5 times than KDP. The NGMBS crystal demonstrated superior resistance to LASER induced damage as compared to urea. [Display omitted] • Sodium guanidinium bis(4-methylbenzenesulfonate) hydrate (NGMBS) is synthesized by solvent evaporation technique. • The estimated energy gap is 4.50 eV; and emission is observed at 567 nm. • The crystal exhibited 2.5 times higher NLO properties than KDP. • Laser damage tolerance value of NGMBS crystal is 22.911 GW/cm2. [ABSTRACT FROM AUTHOR]

Amphibole phenocrysts in post-1 ka lava domes deposits of Taranaki volcano, an andesite arc volcano in New Zealand, provide an opportunity to explore late-stage changes in melt composition and volatiles in the run up to eruption. Amphibole is a subordinate phase (0–7% of modal phenocrysts) and the phenocrysts display three types of growth history. Type 1 are large compositionally and texturally uniform phenocrysts that have low MgO (<13 wt%) and high K 2 O (∼1–1.4 wt%) contents. In contrast, Type 2 have similar cores but have been partially resorbed and overgrown by a mafic rim distinguished by high MgO (up to 15 wt%) and low K 2 O (<1.0 wt%) contents. Type 3 are the least common, and have either normal zoned or concentrically zoned interiors with respect to MgO and FeO. Overall, elemental substitutions and zonation patterns are related to periods of resorption and regrowth that are best explained by changes in melt composition. Based on calculated equilibrium melt compositions, the amphibole crystallisation is consistent with an incrementally grown andesitic to dacitic (SiO 2 58–67 wt%) crystal mush that was periodically recharged with more mafic magma (SiO 2 ∼ 55 wt%). The melts span a compositional gap (SiO 2 ∼ 60–65 wt%) that is not represented in eruption products from the last 8 ka. Such melts were likely brief stages during ongoing fractional crystallisation and magma mixing. Each recharge event disrupted an evolving system and mixed crystals from different parts of it. This concept supports triggering of eruptions by recharge of mafic melts, as also inferred from plagioclase zonation for some eruptions from Taranaki. The outermost rims (0–5 μm) of many amphibole phenocrysts are enriched in fluorine (up to 1.9 wt%) and surrounded by a thick opacitic decomposition growths. We interpret this as the result of slow magmatic ascent and extensive crystallisation that produced a late-stage halogen-rich interstitial melt. This likely extended the conditions for amphibole stability to lower pressure. If F enrichment was accompanied by comparable enrichments in other halogens that preferentially partition into an aqueous phase, then extensive degassing would have occurred during the dome extrusions. • Taranaki andesite dome amphiboles have diverse crystallisation histories. • Amphibole phenocrysts formed in cryptic melts that did not voluminously erupt. • Eruptions were preceded by mafic recharge into a silicic resident mush. • Extensive crystallisation produced late-stage fluorine rich melt. • The dome extrusions were likely associated with extensive degassing. [ABSTRACT FROM AUTHOR]

The hetero-salt, a solid waste, is generated due to the simultaneous crystallization and agglomeration of two or more salts in the evaporative crystallization of multi-salt solution. However, the waste can be transformed into resource if the different crystalline particles can be separated effectively. In this study, NaCl and Na 2 SO 4 were taken as examples and mixed in the solution. It was found that the agglomeration of the crystals occurred both in the drying and crystallization stage. But the crystals could be independent at certain concentration and evaporation time. Meanwhile, the morphological characteristics of NaCl and Na 2 SO 4 crystals were quite different. Therefore, a lab-scale overflow device was prepared to separate the mixed crystals. The results showed that it was possible to separate the two kinds of crystals in simultaneous crystallization effectively. The purity of recovered NaCl was up to 97.58% at a flow velocity of 0.04 m/s. [Display omitted] • Simultaneous crystallization of NaCl and Na 2 SO 4 was studied in the NaCl-Na 2 SO 4 -H 2 O system. • The agglomeration of NaCl and Na 2 SO 4 crystals makes it difficult to separate the two crystals. • The crystals could be isolated under certain conditions during simultaneous crystallization. • The overflow device could separate the two crystals of NaCl and Na 2 SO 4 effectively. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation is as an efficient technique to eradicate toxic chemical pollutants from contaminated water sources. However, the selectivity and photocatalytic activity are the challenging targets to explore the new photocatalysts. Therefore, our research goal is to develop a suitable photocatalyst to satisfy the recent photocatalytic degradation demand. In this work, amine functionalized graphene oxide (NH 2 -GO) supported heterojunction ternary novel nanocomposites (NH 2 -GO/ZnO-WO 3) were prepared via simple solvothermal method. Structural and morphological investigations of the prepared composites are systematically observed by Field Emission Scanning Electron Spectroscopy (FE-SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Ultraviolet–Visible (UV–vis) Spectroscopy. FT-IR analysis confirmed the effective functionalization of amine on graphene oxide. The XRD results indicated that the prepared nanocomposites were free from any impurities and the binary composite (NH 2 -GO/ZnO) showed hexagonal wurtzite structure, whereas the ternary composite (NH 2 -GO/ZnO-WO 3) exhibited mix crystal structure of monoclinic and hexagonal phase of WO 3 and ZnO, respectively. The synthesized ternary photocatalyst (NH 2 -GO/ZnO-WO 3) demonstrated superior photocatalytic efficiency towards various organic dyes such as cationic dye methylene blue (MB, 85.89%) and anionic dye methyl orange (MO, 60.98%) compared to binary photocatalyst (NH 2 -GO/ZnO) that showed only 52.28% of MB and 25.8% of MO dye degradation under UV light irradiation. The enhanced photocatalytic performance was mainly due to the low recombination rate of photogenerated electron-hole pair, narrow band gap, and large surface area of ternary composite. The presence of lone pair electrons in amino group provides a negative-charged surface composite resulting good interaction with cationic dye is the key to upgrade the photocatalytic performance. The ternary nanocomposite NH 2 -GO/ZnO-WO 3 has the capacity to be a competent and acceptable photocatalyst for the photodegradation of organic dyes used in industries. • Synthesis of a novel ternary NH 2 -GO/ZnO-WO 3 nanocomposite by a facile solvothermal method. • XRD, FE-SEM, FT-IR, and UV–Vis corroborated the synthesized composites. • Photocatalytic activity of binary NH 2 -GO/ZnO was improved after supported by WO 3. • NH 2 -GO/ZnO-WO 3 nanocomposite showed enhanced photodegradation under UV light irradiation. • Cationic dye (MB) is more sensitive than anionic dye (MO) towards NH 2 -GO/ZnO-WO 3. [ABSTRACT FROM AUTHOR]

Large-sized single crystals of Na x K 1-x Cl:0.01Ce3+ (with x = 0.2, 0.4, 0.5, 0.6 and 0.8) have been grown by the Czochralski method. The structural, mechanical, electrical and optical properties were characterized by carrying out X-ray diffraction (XRD), X-ray photoelectron spectroscopic (XPS), micro-hardness, DC/AC electrical, optical absorption and luminescence measurements. XRD analysis indicates the two-phased (with two f.c.c. lattices) nature of the mixed crystals and the incorporation of Ce3+ ions into the Na x K 1-x Cl crystal matrix. XPS analysis has verified the dominant presence of Ce3+ (over Ce4+) ion in the Na x K 1-x Cl crystal matrix. Hardness measurement has shown an increase of crystal hardness with Ce3+ doping and maximum hardness for the Na 0.5 K 0.5 Cl:0.01Ce3+ crystal. Electrical measurements indicate that the DC/AC electrical conductivity, dielectric loss factor and dielectric constant of Ce3+ doped crystals increase with the increase in temperature and are larger than that for the un-doped Na 0.5 K 0.5 Cl crystal. Four peaks at 203, 215, 290 and 344 nm are shown by the optical absorption spectra. Photoluminescence excitation and emission peaks due to Ce3+ (4f↔5d) transitions have got influenced by the Ce3+ doping. The TL glow curves of Na x K 1-x Cl:0.01Ce3+ crystals obtained show two peaks at about 72 and 174 °C, Ce3+ ions produce suitable trap depth and result in the characteristic emission. The Na 0.5 K 0.5 Cl:Ce3+ crystal is found to exhibit maximum PL and TL performances. Results obtained indicate that the Na x K 1-x Cl:Ce3+ crystals grown can find their use in luminescence, capacitor and thermoluminescence dosimeter applications. [ABSTRACT FROM AUTHOR]

A series of x at% Gd3+: NaLa 0.975-x Nd 0.025 Gd x (WO 4) 2 mixed crystals were grown by means of the Czochralski method. The mixed crystals are formed by replacing La3+ ions in a part of NaLa(WO 4) 2 host with Gd3+ ions, and the first principle proves that doping Gd3+ improves the disorder and activity of NaLa(WO 4) 2 crystals. For NaLa 0.915 Nd 0.025 Gd 0.06 (WO 4) 2 mixed crystals, the physical and thermal properties were characterized by using structural refinement, infrared spectrum and thermal expansion coefficient. The results show that the grown crystal belongs to the space group Ι 4 1 / a with high phase purity, and has excellent thermal stability and anisotropy. Compared with NaLa 0.975 Nd 0.025 (WO 4) 2 single crystal, with the introduction of Gd3+, the local distortion electric field is generated, the original degenerate state of Nd3+ is changed, and the intensity of Nd3+ emission peak at 1062 nm and 1332 nm is increased by 2.34 and 1.89 times, respectively. The spectral bands of absorption and emission spectra are broadened by about 4 nm. The broadening of spectral band is discussed in detail by using the theory of uniform and non-uniform broadening. For uniform band broadening, the density functional theory is used to calculate the phonon state density and vibration mode of the mixed crystal, and the Raman spectrum proves that the spectral band broadening is caused by the introduction of Gd3+, which generates a new vibrational level and increases the electron-phonon coupling, thus widening the band. For the non-uniform broadening of the spectral band, combined with the variation of the dipole moment caused by the electric field distortion, the spectral band is proved. Finally, the J-O theoretical parameters, absorption and emission cross-sections of mixed crystals are calculated. The experimental results show that NaLa 0.915 Nd 0.025 Gd 0.06 (WO 4) 2 mixed crystals are excellent laser crystal materials, which can improve the utilization of laser pump light and improve the efficiency of laser. • A series of x at% Gd3+, NaLa 0.975-x Nd 0.025 Gd x (WO 4) 2 mixed crystals were grown by means of the Czochralski method. • Compared with NaLa 0.975 Nd 0.025 (WO 4) 2 single crystal, the emission intensity of Nd3+ is increased by 2.34 and 1.89 times • The spectral bands of absorption and emission spectra are broadened by about 4 nm. [ABSTRACT FROM AUTHOR]

TA2 pure titanium (Titan Grade 2-EN) is commonly used in marine and biomedical applications due to its outstanding biocompatibility and resistance to corrosion. Nevertheless, the limited hardness of TA2 presently reduces the service life of the components. Directed energy deposition (DED) technology can improve the properties of conformal materials, opening up new possibilities. In this work, 8% micro-TiC/TA2, 8% nano-TiC/TA2, and 4% micro/4% nano-TiC/TA2 composites were fabricated by DED to investigate the effects of different scales of TiC reinforcement on the properties of TA2. The majority of micro-TiC remaining unmelted in the composite, exhibiting only a small amount of micro-TiC dissolution. In comparison, the nano-TiC/TA2 displays a conspicuous dendritic structure with well-developed dendritic growth, boasting up to three dendrites. In contrast, the 4%micro/4%nano-TiC/TA2 exhibits a mixed crystal morphology, characterized predominantly by dendritic growth along the unmelted TiC, with other TiC phases also present in the deposited layer. Performance tests demonstrated that TiC can increase the microhardness of titanium. The 4% micro/4% nano-TiC/TA2 composite achieved the highest average microhardness of 542 HV 0.2 , representing a 160.58% increase compared to TA2. Additionally, the composites demonstrated improved corrosion resistance relative to TA2, with the 8% micro-TiC/TA2 composite exhibiting the best corrosion resistance. This outcome can be attributed to the effective physical barrier properties of the micron-sized TiC. • The directed energy deposition technique was employed to prepare TiC/TA2 composites. • An innovative proposal was put forth for the simultaneous utilization of micro- and nano-scale TiC-reinforced pure titanium TA2. • This resulted in a remarkable increase of up to 160.78% in the hardness of the composites. • The micron/nano-TiC/TA2 composites exhibited a substantial improvement in both hardness and corrosion resistance when compared to the original materials. [ABSTRACT FROM AUTHOR]

A mixed oxide with the crystal structure of the DyMn 2 O 5 family, namely NdMn 1.5 Ru 0.5 O 5 , is reported active for the oxygen evolution reaction (OER) in acidic media. NdMn 1.5 Ru 0.5 O 5 displays high OER activity of 500 A g Ru −1 at 1.5 V. Moreover, is more stable than most Ru oxides reported to date, remaining active for more than 500 cycles between 1.1. and 1.7 V at low scan rate of 10 mV s−1. The high activity and stability are attributed to the Ru cations, as NdMn 2 O 5 exhibits very low OER activity. NdMn 1.5 Ru 0.5 O 5 has particularly short Ru–Ru distances of 2.60 Å, a value close to the Ru–Ru metallic distances around 2.642 Å. The high activity and durability of NdMn 1.5 Ru 0.5 O 5 for the OER are also demonstrated in a proton exchange membrane water electrolysis cell by producing a low-loaded anode electrode with 0.5 mg Ru cm−2. The cell achieves 1.97 V at 0.5 A cm−2, consistent with the performances reported for Ru-based catalysts but with lower Ru loading. This performance is maintained during 100 h of operation. Additionally, NdMn 1.5 Ru 0.5 O 5 displays visible ORR activity in acidic media, recording an onset potential of 0.85 V at 0.1 mA cm−2. It is noteworthy to highlight the extreme rarity of bifunctional ORR/OER catalysts acidic media. [Display omitted] • NdMn 1.5 Ru 0.5 O 5 exhibits OER activity in acidic media of 500 A g Ru −1@1.5 V. • Stable PEMWE with NdMn 1.5 Ru 0.5 O 5 anode (0.5 mg Ru cm−2) achieved 1.97 V@0.5 A cm−2 • NdMn 1.5 Ru 0.5 O 5 shows bifunctional OER/ORR activity, with a BI of 0.88 V. [ABSTRACT FROM AUTHOR]

• The electrochemical performance of the FeF x @FG(x=2,3) submicron sphere composite cathode material can be attributed to the following three aspects. • Firstly, the discharge behavior of the FeF x @FG(x=2,3) is dominated by FeF 2 , while FeF 3 contributes a high specific capacity to the discharge reaction. • Secondly, 3D nanosphere structure of FeF x @FG(x=2,3) creates high porosity in the composite material,enlarging electrode–electrolyte contact area. • Finally, the FG with semi-ionic C-F bond has provided conductive network for bare FeF x (x=2,3), improving the electrical conductivity of the prepared material. Iron fluoride (FeF 3 and FeF 2) is a potential candidate for the next generation of lithium-ion battery (LIBs) cathode materials due to their high theoretical specific capacity and low cost. However, previous studies have reported that the poor conductivity of FeF 3 and FeF 2 prevents their theoretical specific capacity from being effectively realized. Herein, fluorinated graphene loaded FeF x (FeF x @FG) submicron sphere was synthesized using graphene oxide and utilized as cathode materials for LIBs. Characterization by X-ray diffraction and transmission electron microscopy confirmed that the synthesized FeF x (x = 2 and 3) contains mixed FeF 3 and FeF 2 crystals. The mixed crystal structure enables the FeF x @FG submicron sphere composite to display two steps in the electrochemical reaction when FeF 3 and FeF 2 discharge cooperatively, leading to excellent discharge performance. In addition, since the FG prepared by acid thermal method has good conductivity, it can significantly improve the FeF x conductivity and specific capacity when being connected to FG via C-F bond. The electrochemical tests show that the initial discharge capacity of FeF x @FG is as high as 394.24 mAh/g at the rate of 0.2C in the range of 1.5–4.0 V at 25 °C and display an excellent discharge capacity retention rate after the first discharge process, showing great potential of the mixed crystalline iron fluoride cathode in the field of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • High purity of hafnium carbonitride powders were successfully fabricated by using the CTRN method. • XPS results confirmed that as-prepared powders consisted of Hf-C, Hf-N and C-N bonds. • A possible mechanism of HfC x N y preparation can be described as HfO 2 → HfC x O y → HfC → HfC x N y. • The melting point of as-prepared HfC 0.62 N 0.38 compound is higher than that of commercial HfC. Hafnium carbonitride (HfC x N y) powders have been successfully prepared by heating a mixture of fine-grained HfO 2 and nano-carbon powders during 1873 K-2273 K in nitrogen. The carbothermal reduction nitrdation (CTRN) process is composed of two steps: (1) the formation of microporous HfC and (2) catalytic nitridation of microporous HfC. The results demonstrate that the as-prepared HfC x N y powder consists of a single phase and various nitrogen content through different sintering parameters. The mechanism consists of three stages: (1) Formation of cubic mixed crystal HfC x O y , (2) Transformation into microporous hafnium carbide, and (3) Crucially, microporous hafnium carbide catalyzes the activation and dissociation of nitrogen molecules, leading to the formation of HfC x N y. Additionally, we introduce a laser etching method to confirm the ultra-high-temperature melting behavior of HfC x N y. This study enhances our understanding of HfC x N y powders synthesis and their laser ablation performance, offering valuable insights for future material applications. [ABSTRACT FROM AUTHOR]

The nano SiC coatings were prepared on the surface of graphite by laser irradiation under different laser energy densities (7.07–14.15 kJ/cm2). The influence of laser energy density on the structure and quality of coatings was systematically investigated. The results show that laser irradiation can transform the preset micron-SiC particle coating into nano-SiC particle coating. The nano-SiC coating prepared by laser irradiation can effectively enhance the high temperature oxidation resistance of the graphite substrate. When the laser energy density is 7.07 kJ/cm2, the prepared coating displays a single crystal structure and a good morphology without cracks and spheroidization. The coating prepared under the laser density of 10.61 kJ/cm2 shows a mixed crystal structure with obvious spheroidization. Further increase the laser energy density to 14.15 kJ/cm2, the main structure of prepared coating turns to polycrystalline and obvious cracks can be observed. The cross-section analysis of coating prepared under laser energy density of 7.07 kJ/cm2 indicates that there existed elemental diffusion between the coating and the substrate which increased the adhesion of coating. The calculations based on the Arrhenius formula present that this prepared coating has higher activation energy and therefore it has better high temperature oxidation resistance than the other prepared coatings. [ABSTRACT FROM AUTHOR]

• Zn 2 SnO 4 thin films synthesized by electron beam evaporation were annealed at 500 °C. • Annealed Zn 2 SnO 4 thin films were irradiated with 120 MeV swift heavy ions of Ag+9 for different ion fluences. • The changes in crystal structure and optical properties have been observed after irradiation and are understood by Thermal Spike Model. The structural changes and their effect on optical properties have been studied in Zn 2 SnO 4 thin films irradiated by Ag9+ ions. The irradiation of thin films transforms the mixed crystal structures in to a single diffraction plane. In the XRD, the single peak is the result of atomic jump within the material due to the change in activation energy after irradiation. The XRD and SEM confirmed the modifications of lattice parameters and grains in accordance with the basic requirement of material to be used as transparent conducting oxides. In optical studies, the absorption spectra and Tauc plot confirm the neutralization of free electrons in conduction band minimum which results in an increase in the optical band gap for better transmission in visible range. The results indicate that the swift heavy ions passed from polycrystalline material synergistically with inelastic electronic energy loss to promote the formation of Zn 2 SnO 4 oriented in a single direction and lead to rapid phase transformation. [ABSTRACT FROM AUTHOR]

(1- x)[0.8Na 0.5 Bi 0.5 TiO 3 -0.2K 0.5 Bi 0.5 TiO 3 ]- x BiMn 2/3 Nb 1/3 O 3 ((1- x)NKBT- x BMN with x = 0–0.04) piezoceramics were prepared, the composition-dependent domain structure and domain switching under electric field and their effects on macroscopic electrical properties have been systematically investigated. At room temperature, though the ceramics persists rhombohedral-tetragonal mixed crystal structure, their domain structure evolves from dispersive island-like with average size of 80 nm for x = 0 to labyrinthian-like with average size of 120 nm for x = 0.0075, and then tends to be unobservable by forming polar nanoregions for x = 0.04. As the results, the x = 0.0075 ceramic shows enhanced ferroelectric and piezoelectric property. When compared with the x = 0 pristine counterpart, the saturated polarization, remnant polarization, piezoelectric coefficient, and electromechanical coupling factor of x = 0.0075 ceramic increase by 3%, 12%, 40%, and 20% to 43.2 μC/cm2, 31.2 μC/cm2, 147 pC/N, and 0.28. This work suggests that fine domain engineering is a promising way to further improve electrical property. [ABSTRACT FROM AUTHOR]

• DNA tiles were annealed and assembled into porous crystals by optimized sitting drop growth conditions. • DNA crystal-lanthanide complexes hybrid materials were synthesized. • Curcumin can quench the fluorescence of hybrid luminescent crystals. • Glutathione can change the fluorescence color of hybrid luminescent crystals. In this study, a highly sensitive anticancer drug sensor was synthesized using DNA crystals loaded with luminescent Ln3+(Eu3+/Tb3+) complexes. The sensors exhibited a pronounced color transformation property due to the differential quenching of Eu3+ and Tb3+ emissions upon drug interactions. These luminescent hybrid DNA crystals present a significant advancement in sensing anticancer drugs like curcumin, transitioning from monitoring fluorescence intensity changes to a visually discernable color change. This new approach eliminates the need for specialized instrumentation. Owing to the intrinsic biocompatibility of materials composed of DNA, this hybrid sensor has the potential to sense drugs within the human body. Hybrid crystals loaded with a single complex will lose their fluorescence properties due to drug quenching; however, crystals loaded with mixed complexes emit distinct fluorescent colors, such as yellow-green and orange-red, at different drug concentrations. This color transformation allows for the direct determination of drug concentration based on crystal color, making the sensing process more simple and easily observable. [ABSTRACT FROM AUTHOR]

• A mixed failure mode of slip and cleavage for FCC single crystals is studied. • A novel thermodynamics-based damage evolution model is proposed. • The slip-dominant fracture of a single crystal copper is investigated. • The cleavage-dominant fracture of a nickel-based single crystal alloy is predicted. • The competition effect between slip damage and cleavage damage is revealed. In this study, a microdamage model is newly proposed to predict the failure process of FCC single crystals. Two micro damage mechanisms, slip and cleavage, are both involved in the model. A microscopic damage variable is first defined at the slip plane scale, and a damage coupled crystal plasticity constitutive equation in a co-rotational tensor framework is then established. A damage driving force consisting of generalized energies related to the resolved shear stress and the positive resolved normal stress is proposed to reflect the mixed failure mechanism of FCC single crystals induced by slip and cleavage. The damage evolution equation is then derived in the framework of thermodynamics. An explicit algorithm for the damage coupled crystal plasticity finite element method is given. The proposed microdamage model is utilized to predict the slip-dominant fracture behavior of a single crystal copper and the cleavage-dominant fracture behavior of a nickel-based single crystal alloy. The damage evolution process of slip planes is given and the influence mechanism is revealed. The calculated results agree well with the experimental data, which verifies the good capability of the proposed model in describing and predicting the multi failure processes of FCC metals. Finally, a 2D fracture simulation of a single crystal notched specimen under shear loading is conducted, and the effect of damage parameters on the fracture modes is also discussed. [ABSTRACT FROM AUTHOR]

The conditions of phase formation in the ternary water-salt system comprised of NiSO 4 –CoSO 4 –H 2 O at 25 °C, which is the first step for the creation of structurally perfect mixed crystals Co x Ni (2–x) (SO 4) 2 ·12H 2 O, have been studied. The crystallization regions of tetragonal NiSO 4 ·6H 2 O in the NiSO 4 :CoSO 4 ratio range from 100:0 to 95:5 mass% and monoclinic solid solution of Co x Ni (2–x) (SO 4) 2 ·12H 2 O in the NiSO 4 :CoSO 4 ratio range from 95:5 to 0:100 mass% were delineated. A set of Co x Ni (2–x) (SO 4) 2 ·12H 2 O single crystals in the range of 0.05 ≤ x ≤ 1.95 was obtained. The crystal structures of the samples with x values equal to 1.5, 1.13, and 0.56 have been studied. The Co x Ni (2–x) (SO 4) 2 ·12H 2 O crystals are a series of solid solutions based on the crystal structure of CoSO 4 ·6H 2 O. The transmission spectra in the λ range of 200–800 nm were studied for the obtained crystal samples. A significant decrease in the intensity of the transmission bands in the visible region of the spectrum was observed due to the simultaneous presence of [Ni(H 2 O) 6 ] and [Co(H 2 O) 6 ] complex octahedra in the crystal structures. Consequently, the Co x Ni (2–x) (SO 4) 2 ·12H 2 O crystals are a promising material for optical filters used in photonics. • The conditions of phase formation in system NiSO 4 –CoSO 4 – H 2 O at 25 °C are considered. • A set of Co x Ni (2-x) (SO 4) 2 ·12H 2 O single crystals in the range 0.05 ≤ x ≤ 1.95 was obtained. • The crystal structure of Co x Ni (2-x) (SO 4) 2 ·12H 2 O has been studied. • A transmission spectra was studied for Co x Ni (2-x) (SO 4) 2 ·12H 2 O crystal samples. • Shown the Co x Ni (2-x) (SO 4) 2 ·12H 2 O crystals are a promising material for optical filters which used in photonics. [ABSTRACT FROM AUTHOR]

A new mixed orthophosphate crystal of Nd3+:LuYPO 4 was grown by high temperature solution method successfully. The optical properties including polarized absorption and emission spectra as well as the fluorescence decay curve have been investigated in detail. The calculated absorption cross-sections were 18.6 × 10−20 cm2 at 803 nm with a FWHM of 6.10 nm for π-polarization and 8.96 × 10−20 cm2 at 804 nm with a FWHM of 6.07 nm for σ-polarization, respectively. The broad absorption bands wider than those of Nd:YPO 4 and Nd:LuPO 4 crystals confirm that the incorporation of Lu3+ ions results in a effectively inhomogeneous broadening of the spectra. Based on J-O theory, some typical parameters such as J-O intensity, fluorescence branching rate and radiation lifetime of Nd3+ ions in Nd:LuYPO 4 crystal were systematically calculated. Besides, five strong emission peaks located at 1054, 1061, 1066, 1076 and 1081 nm can be observed obviously from fluorescence spectra. All the results show that Nd:LuYPO 4 crystal is a promising laser material applied to 1.0 μm with multi-wavelength emission characteristics. [Display omitted] • The Nd3+:LuYPO 4 crystal was grown successfully from Pb 2 P 2 O 7 solution. • An effectively inhomogeneous broadening of the spectra at around 808 nm for Nd3+:LuYPO 4 crystal. • Spectral parameters of Nd3+ ions were calculated in detail based on J-O theory. [ABSTRACT FROM AUTHOR]

Prulifloxacin, a broad-spectrum quinolone antibiotic, exhibits three distinct crystal forms, each with different bioavailability and therapeutic properties. It is imperative to assess and control the proportion of each crystal form during the production of raw materials and preparations. Therefore, it is necessary to establish an analytical method that can determine the content of each crystal form in the ternary polycrystalline mixtures. In this study, prulifloxacin crystal forms were analyzed and quantitatively measured using Raman spectroscopy. First, three pure crystal forms of prulifloxacin were prepared under different crystallization conditions and mixed into ternary mixtures at the designed proportions. Subsequently, the ternary mixed crystal samples were analyzed using a Raman microscope.Then run a partial least squares regression analysis to establish a PLS quantitative model using the average spectra data, and a non-negative least squares analysis to establish an area percentage quantitative model using Raman imaging data.The method validation results showed that the two models successfully predicted the proportion of each crystal form within the prulifloxacin polycrystalline mixtures, with a prediction accuracy of less than ± 10 %. Raman spectroscopy was thus established as an effective method for crystal form analysis and quantitative measurement of prulifloxacin. [Display omitted] • Studied the percentage of each crystal form of prulifloxacin by Raman technology. • Established a PLS quantitative model using Raman spectra. • Established an area percentage quantitative model using Raman imaging maps. • The method validation results showed that both models were precise and accurate. [ABSTRACT FROM AUTHOR]

Here we present the study of spectral and kinetic characteristics of Er3+ ions in the heavily doped BaY 1.8 Lu 0.2 F 8 mixed crystals, which are homologous to well-known fluoride host BaY 2 F 8 with high value of crystal field splitting. Absorption and luminescence spectra were registered, and the luminescence decay was studied in the IR spectral range for BaY 1.8 Lu 0.2 F 8 crystals doped with Er3+ ions at concentrations of 20.0 at. % and 30.0 at. %. Based on the Judd-Ofelt theory, the intensity parameters were determined from the absorption spectra with the use of two approaches, the standard theory (J-O), and the intermediate configuration interaction (ICI). It is shown that investigated BaY 1.8 Lu 0.2 F 8 :Er3+ crystals propose the value of stimulated emission cross-section at the wavelength around 2.7 μm higher than that for Er-doped YAG and at the level of Er-doped LiYF 4 crystals. In addition, it was shown that for BaY 1.8 Lu 0.2 F 8 crystals with a high doping level of Er3+ (more than 20.0 at. %), the radiative lifetime of the 4I 13/2 state becomes shorter than the lifetime of the 4I 11/2 state, which speaks for success on efficient laser oscillation at a wavelength of about 2.7 μm (the 4I 11/2 → 4I 13/2 transition). • Stimulated emission cross-section around 2700 nm is higher in BaY 1.8 Lu 0.2 F 8 :Er than in YAG:Er and at the level of LiYF 4 :Er. • Lu3+ doping led to larger total spectral width of 4I 11/2. → 4I 15/2 and 4I 11/2 → 4I 13/2 transitions in BaY 1.8 Lu 0.2 F 8 :Er crystals compared to Er:LiYF 4 • Lifetime of 4I 13/2 becomes shorter than 4I 11/2 in BaY 1.8 Lu 0.2 F 8 with a high doping level of Er3+ (more than 20 %). • The Judd-Ofelt analysis for BaY 1.8 Lu 0.2 F 8 :Er with the ICI approach agreed better with experimental data. [ABSTRACT FROM AUTHOR]

High efficient Na 3 (Lu 1-x Eu x)(PO 4) 2 orthophosphates phosphors were synthesized by conventional solid state reaction method. The obtained phosphors crystallized in the orthorhombic system with the space group Pca 2 1. Since the crystal structure of the phosphor is composed of isolated PO 4 tetrahedra, the average distance between rare earth ions was distant. As the concentration of Eu3+ activator ion reaches to 100%, reduced Judd-Ofelt parameter ratio of Ω 2 /Ω 4 implies the improvement of the symmetry environment around Eu3+ ion and from the prolonged lifetime of 5D 0 →7F 2 transition we inferred no-concentration quenching in this phosphor. Furthermore, due to the better crystallinity of Na 3 Eu(PO 4) 2 phosphor compared to the mixed crystals Na 3 (Lu 1-x Eu x)(PO 4) 2, the internal quantum efficiency of the Na 3 Eu(PO 4) 2 phosphor reaches the high value up to 99% under near-ultraviolet (393 nm) excitation. Temperature dependent emission spectra revealed that Na 3 Eu(PO 4) 2 phosphor possesses stable emission of 80% at 423 K compared to room temperature. Due to high quantum efficiency and excellent thermal stability, Na 3 Eu(PO 4) 2 has potential application as reddish-orange phosphors. • Judd-Ofelt parameter implies improvement of the symmetry around Eu3+ ion. • The prolonged lifetime certifies no-concentration quenching until the 100 at % Eu3+. • The quantum efficiency of Na 3 Eu(PO 4) 2 phosphor reaches the high value up to 99%. • Excellent thermal stability up to 80% at 423 K compared to room temperature. [ABSTRACT FROM AUTHOR]

Plasma nitriding was performed on samples of JIS SKD61 die steel, and the microstructure near the surface was analyzed. The plasma nitriding was performed using active screen plasma (ASP). In the ASP nitriding process, a dependency on the bias current applied to the sample was found. Emission spectra showed the presence of atomic nitrogen ions (N+), molecular nitrogen ions (N 2 +), hydrogen radicals (H), nitrogen radicals (N), and radicals consisting of nitrogen and hydrogen (N i H i). The densities of nitrogen and hydrogen radicals observed by vacuum ultraviolet absorption spectroscopy were 1.5 × 1011 and 1.0 × 1011 cm−3, respectively. Once the device current reached 0.25 A or more, the surface became cloudy. The cause of this cloudiness was investigated by X-ray diffraction and cross-sectional bright-field scanning transmission electron microscopy and was found to be a deposition layer around 50 nm thick of a mixed crystal containing the ε phase Fe 2 3 N and γ' phase Fe 4 N and the formation of a structure with a period of around 300 nm at the surface. Although deposition of Fe 2 3 N and Fe 4 N also occurred at the surface in samples without cloudiness, the deposition layer was only around 10 nm thick, and no periodic structure was formed. A chromium oxide-rich layer was found directly under the Fe 2 3 N and Fe 4 N deposition layer by scanning transmission electron microscopy with electron energy-loss spectroscopy. This chromium oxide-rich layer likely occurred due to selective etching of iron oxide and chromium oxide. In ASP nitriding method, the sputtering action of charged particles of N 2 + and N+ was experimentally shown to play an important role in nitriding and surface morphology. Furthermore, it was discovered that there was no compound layer several micrometers thick as would form in the conventional nitriding process. • Active screen plasma nitriding was performed on samples of JIS SKD61. • Ion bombardment played an important role in nitriding and surface morphology. • Ion bombardment was controlled by the specimen bias current. • Surface characteristics were analyzed by STEM-EELS. • A chromium oxide-rich layer was found directly under the deposition layer. [ABSTRACT FROM AUTHOR]

The structural, elastic and optical properties of the ternary mixed crystals (TMCs) zinc-blende In x Ga 1- x As for the In-composition varying from 0.0 to 1.0 by step of 0.125 are calculated by first-principle. We have adopted 16-atoms supercell structures of the In x Ga 1- x As in this work, and the results for the equilibrium lattice constants, the elastic constants and the optical properties such as real and imaginary parts of the dielectric function, absorption coefficient, reflectivity, refractive index, extinction coefficient, energy loss function and real component of optical conductivity are presented and discussed in detail. The results show that the lattice constants vary with the composition almost linearly following the Vegard's law. Elastic properties such as bulk modulus B , shear modulus G and Young's modulus E decreases monotonically and non-linearly with increasing the alloy composition x. TMCs In x Ga 1- x As are anisotropic and mechanically stable. And GaAs may be a less compressible alloy. The static dielectric constant, the static reflectivity and the static refractive index of optical parameters increases with increasing of indium composition. The incorporation of indium composition of absorption spectra leads to the redshifts phenomenon of optical absorption edge and a strong absorption is appeared from near visible to UV range. For x = 0.125, the energy loss function occurs a maximum value so-called plasmon frequency at 15.4eV and there is intense optical conductivity at lower photon energy range. [ABSTRACT FROM AUTHOR]

• 2D MoS 2 and WS 2 nanosheets were synthesized by means of a CVD method. • A novel Nd:GdYNbO 4 mixed crystal was grown and used as laser medium. • Pulsed MoS 2 /WS 2 Nd:GdYNbO 4 lasers performance was demonstrated for the first time. Utilizing the saturable absorption characteristics of transition metal dichalcogenides (TMDs), a passively Q-switched 1066 nm laser based on a novel Nd:GdYNbO 4 mixed crystal as well as a two-dimensional (2D) layered molybdenum disulfide (MoS 2) and tungsten disulfide (WS 2) was realized for the first time. The highest repetition rate, the shortest pulse width and maximum peak power were 172 kHz, 723 ns and 0.85 W for Nd:GdYNbO 4 /WS 2 laser, respectively. The corresponding values for the Nd:GdYNbO 4 /MoS 2 laser were 122 kHz, 532 ns and 1.63 W. Furthermore, it was found that WS 2 required a lower excitation energy, while a MoS 2 nanosheet exhibits a deeper modulation depth. [ABSTRACT FROM AUTHOR]

Delafossite CuFeO 2 is a promising material for heterogeneous activation of peroxymonosulfate (PMS), while effect of different crystal types on its activity has not been reported. In this work, pure rhombohedral CuFeO 2 (3R-CFO) and a mixture of rhombohedral and hexagonal phases CuFeO 2 ((3R + 2H)-CFO) are successfully synthesized by a simple hydrothermal method, and an efficient PMS activation system is set up. Compared with pure 3R-CFO, the introduction of hexagonal phase (2H-CFO) markedly enhances the removal of Orange I (OI). Visible-light response accelerating PMS conversion is observed, and 3R-CFO plays a critical role in such synergetic reaction under natural light illumination. Moreover, it is uncovered that the mixed (3R + 2H)-CFO crystals enhance the exposed Lewis sites of Cu+ and Fe3+, the concentration of surface hydroxyl groups, and the electron transfer. These are important for excellent activity of (3R + 2H)-CFO. SO 4 − and OH both take part in the oxidation process, accompanying the dominant contribution of SO 4 −. The electron transfer of Cu2+/Cu+ and Fe3+/Fe2+ cycles facilitates the decomposition of PMS to generate reactive radicals. Unlabelled Image • Mixed phases CuFeO 2 are synthesized as a heterogeneous catalyst. • This catalyst shows a high catalytic activity towards PMS activation. • The synergistic effect of Cu+ and Fe3+ accelerate PMS activation and OI removal. [ABSTRACT FROM AUTHOR]

Optical absorption of exciton transitions in asymmetry Zn 1 − x Mg x O/ZnO/Zn 1 − y Mg y O quantum wells (QWs) is investigated and the effects of size and ternary mixed crystals (TMCs) are discussed in a wider TMC region. The different exciton states and interstate transition energies are obtained by the combination of a variational method and numerical calculations. Based on the density matrix approach and our weight model, the mixed phase of wurtzite and zinc blende in Zn 1 − x Mg x O alloys within 0.37< x <0.62 is considered to discuss the optical absorption coefficients (OACs) in the presence of built-in electric fields and the Hartree potential. The results show that the peaks of OACs appear a merged phenomenon under size modulation. The change of OACs in wurtzite–wurtzite–wurtzite QWs is more obvious than that in zinc blende–wurtzite–zinc blende ones with increase of Mg component to demonstrate the TMCs effect. Our results are better agreement with the photoluminescence spectra of exciton transitions given by experiments. • Obtaining exciton transition energy in two kinds of quantum wells with mixed phases. • Optical absorption coefficients appear two peaks in the mixed phase region. • Optical absorption coefficients in two kinds of quantum wells merge together. [ABSTRACT FROM AUTHOR]

Highlights • A novel Nd:GdLaNbO 4 mixed crystal was investigated and used as laser medium. • A two-dimensional WS 2 nanosheet was prepared and served as saturable absorber. • The Q-switched Nd:GdLaNbO 4 laser based on WS 2 was demonstrated for the first time. Abstract In this paper, we present a diode-pumped passively Q-switched laser based on a novel Nd:Gd 0.89 La 0.1 NbO 4 mixed crystal and two-dimensional (2D) tungsten disulfide (WS 2) saturable absorber. After the optimization of the laser parameters, a maximum continuous-wave (CW) output power of 4.37 W with a slope efficiency of 42% was obtained, which is the highest output power to the best of our knowledge. Utilizing the saturable absorption characteristic of the 2D WS 2 material, the pulsed Nd:Gd 0.89 La 0.1 NbO 4 laser performance was investigated. The shortest pulse duration of 895 ns and the highest repetition rate of 162 kHz were realized at an absorbed pump power of 7.18 W. [ABSTRACT FROM AUTHOR]

Abstract 0.45 at. % Yb doped La 0.11 Y 0.89 VO 4 and La 0.15 Y 0.85 VO 4 mixed crystals were grown by the Czochralski method, the structures and polarized spectroscopic properties were systematically studied. The fluorescence lifetimes of these two crystals were 355 and 374 μs, respectively. Continuous wave laser performances of the a -cut mixed crystals were demonstrated, with Yb:La 0.11 Y 0.89 VO 4 , a maximum output power of 1.97 W was achieved at the absorbed pump power of 7.58 W. Passive Q-switched laser with MoS 2 as saturable absorber was also achieved, and the maximum average output power was 82 mW at a repetition rate of 200 kHz with a slope efficiency of 20%. Graphical abstract Image 1 Highlights • High-quality Yb:La 0.11 Y 0.89 VO 4 and Yb:La 0.15 Y 0.85 VO 4 mixed crystals were grown by the Czochralski method. • The structures and polarized spectroscopic properties were systematically studied. • Continuous wave laser performances were demonstrated, a maximum output power of 1.97 W was obtained. • Passive Q-switched laser with MoS 2 as saturable absorber was achieved. [ABSTRACT FROM AUTHOR]

The doubly and mono doped nanocrystalline mixed oxides Ce 1-x-y Yb y Pd x O 2-δ (y up to 0.4, x up to 0.2) were synthesized with the reversed microemulsion method. The morphology, microstructure and composition of the samples were investigated by TEM, EDS, XRD, XAFS, and DFT calculations of XANES spectra. The main aim of the study was the determination of the influence of an additional ytterbium content on structural and electronic properties of the Pd-doped ceria mixed oxide, i.e., the comparative discussion of the results obtained for Ce 1-x Pd x O 2-δ and Ce 1-x-y Yb y Pd x O 2-δ. All samples were homogeneous fluorite-type nanocrystallites with very small size (3–5 nm). Reducibility studies revealed strong hydrogen consumption in these systems at low temperatures without any changes of their structure. The XANES and EXAFS spectra for Ce 1-x-y Yb y Pd x O 2-δ indicate a partial reduction of palladium at 200 °C and almost complete (90%) at 500 °C in hydrogen. The presence of ytterbium in Ce 1-x-y Yb y Pd x O 2-δ prevents the formation of metallic particles in reducing atmosphere (up to 500 °C) and strongly inhibits crystal growth of the mixed oxide. • The Ce 1-x-y Yb y Pd x O 2-δ are homogeneous nanocrystalline mixed oxides (3–5 nm). • The introduction of more than one dopant in ceria inhibits the sintering of the crystallites. • Presence of Yb in Ce 1-x-y Yb y Pd x O 2-δ a prevents the formation of Pd clusters up to 500 °C in H 2. [ABSTRACT FROM AUTHOR]

• A novel Nd:Gd 0.69 Y 0.3 NbO 4 mixed crystal was used as laser gain medium. • A 2D MoS 2 nanosheet was used as saturable absorber. • A 2D MoS 2 passively Q-switched Nd:GdYNbO 4 laser was demonstrated for the first time. A diode-pumped MoS 2 passively Q-switched Nd:Gd 0.69 Y 0.3 NbO 4 laser at 1066 nm was demonstrated for the first time. The maximum continuous (CW) wave output power of 1.77 W was obtained when the absorbed pump power was 7.28 W and the transmission of flat output coupler was 25%. The maximum slope efficiency reached 33.3%. The pulsed laser with high repetition rate was obtained when the two-dimensional (2D) MoS 2 material was used as the saturable absorber. The highest repetition rate and the narrowest pulse width were reached 112 kHz and 532 ns, respectively. [ABSTRACT FROM AUTHOR]

Abstract The structure and optical properties of Bridgman-grown (Cu 6 PS 5 Br) 1- x (Cu 7 PS 6) x mixed crystals are reported. X-ray diffraction data reveal a face-centred cubic lattice (F 4 ¯ 3 m space group) for Cu 6 PS 5 Br-rich crystals (0 < x < 0.4) and a primitive cubic lattice (P 2 1 3 space group) for Cu 7 PS 6 -rich (0.4 < x < 1) crystals. These structural data correlate with the Raman spectra where, besides the common features typical for the argyrodite-type Cu 6 PS 5 Br and Cu 7 PS 6 crystals, weaker bands characteristic only for the end-point compounds are observed in the corresponding compositional intervals. Based on the spectral position of the short-wavelength edge of diffuse reflection spectra, the compositional dependence of the energy gap is studied exhibiting a nonlinear behaviour. Graphical abstract Image 1 Highlights • Structure and optical properties of (Cu 6 PS 5 Br) 1- x (Cu 7 PS 6) x crystals are reported. • Structural data of (Cu 6 PS 5 Br) 1- x (Cu 7 PS 6) x crystals correlate with Raman spectra. • Compositional dependence of the energy gap shows the nonlinear behaviour. [ABSTRACT FROM AUTHOR]

Highlights • We synthesized polycrystals of mixed crystals of spinels A(Cr,Fe) 2 O 4 (A = Zn and Cd). • The magnetic susceptibility measurements reveal spin-glass-like behavior below ∼10 K. • The Weiss temperatures suggest the generation of bond frustration. • The Weiss temperatures suggest the competition of bond and geometrical frustrations. Abstract We investigate magnetic properties of mixed crystals of spinel oxides Zn(Cr 1− x Fe x) 2 O 4 and Cd(Cr 1− x Fe x) 2 O 4 to study Cr-site substitution effects on the geometrically-frustrated magnetism of chromite spinels ZnCr 2 O 4 and CdCr 2 O 4. Zn(Cr 1− x Fe x) 2 O 4 and Cd(Cr 1− x Fe x) 2 O 4 with above x ∼ 0.1 exhibit spin-glass-like behavior below ∼10 K which is suppressed by magnetic field H > 1 kOe. Moreover, the Fe concentration x dependence of Weiss temperature Θ W in Zn(Cr 1− x Fe x) 2 O 4 (Cd(Cr 1− x Fe x) 2 O 4) exhibits the sign change of Θ W from negative below x ∼ 0.4 (x ∼ 0.1) to positive above x ∼ 0.4 (x ∼ 0.1). This suggests that, in Zn(Cr 1− x Fe x) 2 O 4 and Cd(Cr 1− x Fe x) 2 O 4 , the competition of antiferromagnetic and ferromagnetic interactions (bond frustration) becomes stronger with increasing the Fe concentration x , while the geometrical frustration becomes weaker with increasing x. [ABSTRACT FROM AUTHOR]

Highlights • 4F 3/2 → 4I 9/2 laser transition at 928 nm in a Nd:GYTO mixed crystal is realized. • A comparative study of emission was performed under the pump at 808 nm and 879 nm. • Improved performances were achieved under direct pumping into the emitting level. Abstract We report on a 928 nm laser based on quasi-three-level transition of 4F 3/2 → 4I 9/2 in a Nd:Gd 0.69 Y 0.3 TaO 4 mixed single crystal. With LD pumping at 808 nm, an output energy of 29.8 mJ at 928 nm is achieved with an optical-to-optical efficiency of 16.5% and a slope efficiency of 21.2%. In comparison, using 879 nm LD pumping, the maximum output energy at 928 nm reaches 48.5 mJ with an optical-to-optical efficiency of 33.4% and a slope efficiency of 38.0%. [ABSTRACT FROM AUTHOR]

Abstract A diode-pumped continuous-wave (CW) laser with a novel Nd:GdLaNbO 4 mixed crystal at 1065 nm was demonstrated. The influence of various parameters on CW output performance was investigated theoretically and experimentally, including the transmission of output mirror, the resonance length and the focusing radius of pump light. When the resonator length was 40 mm and the focusing radius of pump light was 256 μm, the maximum output power of 3.06 W was obtained with optimum output mirror transmission of 20% at absorbed pump power of 12.24 W. The corresponding slope efficiency was 29.1%. [ABSTRACT FROM AUTHOR]

Abstract The optical properties of beryllium doped zinc oxide (Be x Zn 1-x O) ternary mixed crystal are studied by the first-principles calculations within the framework of the density functional theory (DFT). It turned out that as the energy increases the real parεt ε 1 of the dielectric function of Be x Zn 1-x O first reached a maximum peak and then gradually attenuated, the static dielectric constant of Be x Zn 1-x O decreases as the Be component increases, the imaginary part ε 2 of the dielectric function represents light absorption, as the Be component increases, the three main peaks are constantly moving towards the high-energy tail. The refractive index and reflectivity of Be x Zn 1-x O ternary mixed crystal are decreases with increasing Be concentrations, the blue shift of absorption spectrum of the system becomes more significant. Obtained smooth varying of the optical properties is related to the gradual decreasing of the lattice parameter of Be x Zn 1-x O and increasing of the bandgap. [ABSTRACT FROM AUTHOR]

The binary and ternary telluride systems containing europium as one of the magnetic components exhibit a higher effective g factor and much lower effective mass due to strong spin-orbit and s/p-f hybridized interaction mediated by the dopant impurity. In this communication, we have exploited the same for a ternary mixed crystal S n 1 − x S r x T e , with strontium as the non-magnetic counterpart of europium. We have derived a functional equation within the framework of effective mass representation, accounting for both spin-orbit interaction and the presence of a magnetic field. In the context of k → ⋅ π → model, at first, two MW (Mitchell-Wallis) band edge states are diagonalized properly, and subsequently, the off-band edge states are treated using perturbation up to the k 2 level. We derived the formulas for the effective g factor and effective mass by employing Green's function method, considering the presence of spin-orbit interaction, magnetic field, and Sr impurity and assuming band inversion model as applicable to S n 1 − x S r x T e system. Finally, we conduct a comprehensive examination of the effective g factor, effective mass, and their respective anisotropies in S n 1 − x S r x T e considering their dependence on carrier concentration and impurity levels at T = 300 K. We present extremely elevated effective g factor; g = 2230 , for n − S n 1 − x S r x T e and g = 2160 , for p − S n 1 − x S r x T e respectively with large anisotropies and correspondingly low effective mass m c , v = 0.003 m 0 around x = 0.014 in the concentration range 0.01 × 10 19 cm − 3 to 0.1 × 10 19 cm − 3. Irrespective of the unsaturated electronic shell of Sr , the existence of strong spin-orbit interaction refers to the strong coupling of band edge states across the band minima triggered by substitutional impurity. The occurrence of a substantial effective g factor and low effective mass is unique in such non-magnetic S n 1 − x S r x T e mixed crystal ever reported. • Giant effective g factor; g = 2230 for n − S n 1 − x S r x T e and g = 2160 for p − S n 1 − x S r x T e are reported. • Mostly prominent in telluride and selenide group of binary and ternary compounds like E u T e , E u S e S n 1 − x E u x T e and P b x E u 1 − x T e. • Effective masses as low as m c , v = 0.003 m 0 both for n- S n 1 − x S r x T e and p- S n 1 − x S r x T e are also found. • Calculated parametric anomalies attributes to the strong S.O interaction and band inversion mediated by Sr impurity. • Anisotropic large effective g factor and correspodingly low effective mass makes S n 1 − x S r x T e , a potential choice for spintronics application. [ABSTRACT FROM AUTHOR]

• MW-assisted solvothermal method provide the synthesis of the CZTS NCs with controlled optical properties. • Surface modification of the CZTS NCs with o-phenylenediamine(O-PHA)improved the charge transfer properties of the NCs. • PV efficiency was improved ∼5 timesdue to the adding of CZTS NCs modified with O-PHAcompared to unmodified CZTS NCs. • CZTS NCs can be used asthe donorof electrons in the active layer of the hybrid organic-inorganic PV. Environmentally friendly, colloidal nanocrystals (NCs) are promising materials for the next-generation, hybrid organic-inorganic photovoltaic devices obtained by solution-based methods because of their low cost, solution processability, and facile bandgap tunability. In this work, Cu 2 ZnSnS 4 nanocrystals (CZTS NCs) with a diameter of 5 nm and the mixed crystal structure, including the kesterite and wurtzite phases, were synthesized using a "green" microwave-assisted process. The as-synthesized CZTS NCs were characterized with XRD, TEM, UV–Vis spectroscopy, PL spectroscopy, EDS, AFT-IR, XPS, and Raman spectroscopy. The photovoltaic (PV) performance of hybrid devices was studied and it consisted of ITO/PEDOT:PSS/active layer/Al, where CZTS NCs, model polymer PCDTBT, and PC 70 BM as an acceptor of electrons were in the active layer. In order to improve the charge transport and hydrophobicity of CZTS NCs in hybrid solar cells, the surface of the NCs was modified with four selected aromatic molecules, e.g. 1-aminonaphthalene, o-phenylenediamine, 2-naphthalenethiol, and 2-naphtholic acid, respectively. The performance of the devices significantly depended on the type of the used target ligand for modification of the CZTS NCs and their concentration in the active layer. With a fixed concentration of NCs, the exchange of ligand from initial ethylenediamine, in the best case of o-phenylenediamine, results in a five-time boost in device efficiency. This optimization of the NC ligands also allows achieving c.a. 45 % relative increase in device efficiency compared to the reference system without NCs. The highest average photovoltaic efficiency of 2.82 % with the open circuit voltage (V oc) = 0.86 V, short circuit current density (J sc) = 8.79 mA/cm2, and fill factor (FF) = 0.41 was noted. [Display omitted] [ABSTRACT FROM AUTHOR]

Tm3+-doped CaY 0.9 Lu 0.1 AlO 4 single crystal was successfully grown by the Czochralski method. The crystal structure, polarized absorption spectra and polarized emission spectra of Tm:CaY 0.9 Lu 0.1 AlO 4 crystals were investigated. By using the Judd–Ofelt approach, the intensity parameters Ω 2,4,6 , spontaneous transition rate, branching ratios and radiative lifetimes were calculated. Diode-end-pumped continuous-wave Tm:CaY 0.9 Lu 0.1 AlO 4 lasers have also been investigated by establishing a simple and compact plane-concave cavity with four differently coated output couplers. Four different lasing wavelengths at about 2029 nm, 2000 nm, 1966 nm and 1888 nm have been achieved with maximum output power and slope efficiency of (1.98 W, 15.1%), (5.89 W, 46.2%), (6.92 W, 54.9%) and (5.54 W, 44.7%), respectively. The results in regard to the broad emission spectra and good laser performance show that the Tm:CaY 0.9 Lu 0.1 AlO 4 mixed crystal could be very promising for broadband tunable and/or femtosecond ultrafast laser generation in the important 2-μm spectral region. • Tm:CaY 0.9 Lu 0.1 AlO 4 crystal was grown by the Czochralski method. • The crystal structure, polarized spectra were investigated. • The maximum output power of 6.92 W with slope efficiency 54.9% was achieved. [ABSTRACT FROM AUTHOR]

Vermiculite undergoes significant changes in mineralogical characteristics upon chemical (with H 2 O 2) and thermal (roasting) expansions, resulting in a marked impact on its adsorption behavior toward Pb(II) removal. Both chemical and thermal expansions exfoliated the tightly-stacked bulk structure of raw vermiculite into ultra-thin sheets and built abundantly nanoporous channels in the lamellar region, offering sufficient adsorption sites. Meanwhile, the surface properties of hydrophilicity and negative charge in raw vermiculite remain unaltered during expansions, thus enabling an enhanced adsorption capacity through electrostatic attraction. However, severe loss of cation exchange capacity and structural hydroxyl groups due to thermal expansion damaged mixed crystal phases in vermiculite and hydrophlogopite, leading to the poorer Pb(II) removal capability. The results demonstrate that the favorable influence of chemical expansion in raw vermiculite for Pb(II) removal is attributed to enhanced cation exchange within the interlayer, functional groups of structural hydroxyl and siloxane, and negative surface charge on hydrophilic surface. [Display omitted] • Both thermal and chemical expansions form nanoporous structures with abundant adsorption sites. • Hydrophilicity and negative charge enhance adsorption capacity through electrostatic attraction. • Thermal expansion reduces adsorption capacity by decreasing cation exchange and hydroxyl groups. • Chemical expansion is a favor for Pb(II) adsorption due to enhanced cation exchange. [ABSTRACT FROM AUTHOR]

Optical phonons significantly relate to fundamental limits on dynamical processes in layered polar semiconductor devices. MgZnO layers commonly serve as barriers of ZnO quantum wells (QWs) to improve the electric and optical properties by quantum confinement while keeping the Mg fraction below 0.4 to avoid the crystal phase transformation from wurtzite to rocksalt. This work investigates ternary mixed crystal effects on optical phonons in wurtzite ZnO quantum well with asymmetric barriers of Mg x Zn 1- x O and Mg y Zn 1- y O over a full range of Mg mole fractions. Since MgZnO could be wurtzite (WZ) and rocksalt (RS) phases, the QWs can be denoted as WZ/WZ/WZ, WZ/WZ/RS, and RS/WZ/RS, respectively. Both asymmetries in the Mg fractions and crystal structures of the two barriers affect the optical phonons in QWs. RS/RS/RS quantum wells are also discussed for comparison. Since oscillatoring electrostatic potential of optical phonons is only permitted in the anisotropic wurtzite but forbidden in istropic rocksalt, more modes of confined optical phonons are found in a WZ/WZ/WZ QW, followed by WZ/WZ/RS one, and the least in the RS/WZ/RS one, while there is no confined optical phonons in RS/RS/RS quantum wells. Besides, the difference between the Mg fractions in two barriers leads to more modes of interface optical phonons due to the two unequal interfaces. The modes contained in the optical phonons spectra as well as their frequency ranges, dispersion relations, and electrostatic potentials, vary with Mg fraction in barriers. The strain on interfaces induced by the lattice mismatch leads to a slight blue shift of the dispersion relation as Mg fraction increases. Based on the results of this paper, the optical phonons related to electronic and optoelectronic properties in QWs could be further understood and adjusted. • Mg mole fractions and crystal structures lead to ternary mixed crystal effects on optical phonons in Mg x Zn 1- x O/ZnO/Mg y Zn 1- y O quantum wells. • The dispersions and electrostatic potentials of optical phonons in quantum wells vary with crystal structures and Mg mole fraction. • The asymmetric wurtzite produces confined optical phonons and different in Mg mole fractions leads to interface optical phonons. [ABSTRACT FROM AUTHOR]