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Ferroelectric HfO2-based materials hold great potential for widespread integration of ferroelectricity into modern electronics due to their robust ferroelectric properties at the nanoscale and compatibility with the existing Si technology. Earlier work indicated that the nanometer crystal grain size was crucial for stabilization of the ferroelectric phase of hafnia. This constraint caused high density of unavoidable structural defects of the HfO2-based ferroelectrics, obscuring the intrinsic ferroelectricity inherited from the crystal space group of bulk HfO2. Here, we demonstrate the intrinsic ferroelectricity in Y-doped HfO2 films of high crystallinity. Contrary to the common expectation, we show that in the 5% Y-doped HfO2 epitaxial thin films, high crystallinity enhances the spontaneous polarization up to a record-high 50 µC/cm2 value at room temperature. The high spontaneous polarization persists at reduced temperature, with polarization values consistent with our theoretical predictions, indicating the dominant contribution from the intrinsic ferroelectricity. The crystal structure of these films reveals the Pca21 orthorhombic phase with a small rhombohedral distortion, underlining the role of the anisotropic stress and strain. These results open a pathway to controlling the intrinsic ferroelectricity in the HfO2-based materials and optimizing their performance in applications.

The light rare earth Pr/Ce-contained (Tb0.2Pr0.8)1–xCexFe1.93 (0 ≤ x ≤ 1.0) intermetallics were arc melted and magnetoelastic properties were investigated. The compounds of x ≥ 0.40 are found to stabilize at ambient pressure in a single Laves phase with MgCu2-type C15 structure, which is attributed to the strong Ce 4f bonding. The mixed-valence behavior, with a support of the deviation from the linear Vegard’s law for both lattice parameter a and saturation magnetization MS, is observed at room temperature. The easy magnetization direction (EMD) was determined by the analysis of XRD on both magnetically aligned samples and the (440) splitting, that is, EMD lies toward axis for x ≤ 0.50 rotating to for x = 0.60, accompanied with the structural distortion from rhombohedral to orthorhombic. The substitution of Ce for Tb/Pr is conductive to the reduction of magnetocrystalline anisotropy, giving rise to an improvement of the low-field magnetostriction. The excellent magnetoelastic properties can be tailored by the Ce introduction, e.g., the spontaneous magnetostriction coefficient λ111 as large as 1150 × 10−6 for x = 0.40, and the low-field induced magnetostriction achieving a high value of λa = 180 × 10−6 at 80 kA/m for x = 0.60. The excellent magnetoelastic properties and the combination in high Pr-content with low cost, suggest promising prospects in applications.

Structural, optical and magnetic properties are reported for new synthesized perovskite materials. Ba0.3La0.7Ti0.3Fe0.7O3 and Ba0.1La0.9Ti0.1Fe0.9O3 compositions were prepared via solid state reaction. X-ray analysis confirms that both compositions show feature of perovskite structure. Rietveld refinement method was used to confirm the phase formation and investigate the structure and space group. The study demonstrates the formation of orthorhombic structure with Pnma space group for Ba0.3La0.7Ti0.3Fe0.7O3 while the composition Ba0.1La0.9Ti0.1Fe0.9O3 structure adopts Pbnm symmetry. UV-vis spectroscopy measurements show very broad and intense UV-visible light absorption, the estimated band gap ranges between 2.07 and 2.15 eV. Magnetic measurements were carried out for the compositions Ba0.3La0.7Ti0.3Fe0.7O3 and Ba0.1La0.9Ti0.1Fe0.9O3. The hysteresis loop of both samples at 300 and 10 K show a strong ferromagnetic behavior. The temperature dependent magnetization at 0.05 T under field-cooled (FC) and zero field cooled (ZFC) modes shows magnetic frustration or spin glass-like behavior.

Crystal lattice structure searching by Particle Swarm Optimization (PSO) and first-principles structural optimization have been used to explore polymorphs of BC2N, possessing sp3 hybridization, under a varying applied hydrostatic pressure. Two low Gibbs free energy structures were identified: one with a primitive orthorhombic structure and Space Group, Pmm2, and the other with a primitive tetragonal structure and Space Group, P m2. Dynamical and mechanical stabilities of the Pmm2, orthorhombic BC2N (o-BC2N) structure were established using its phonon dispersions and elastic constants. The bulk modulus of this predicted BC2N phase was 377.15 GPa, which indicates a super-hard compound. The material is brittle with a B/G ratio of 0.911 and a low degree of elastic anisotropy with a Universal Elastic Anisotropy Index of only 0.774%. Calculations of the electronic band structure demonstrated that the material is a direct band gap semiconductor with a band gap of 1.731 eV at zero applied pressure. The band gap increases monotonically with increased applied pressure and saturates to a value of about 1.756 eV above 1500 kbars; the hydrostatic pressure coefficients associated with this process were determined. Key words: High pressure phase stability, elastic anisotropy, ultra-hard material.

GaN1−xZnOx solid solution has emerged as a promising candidate to generate clean and sustainable hydrogen energy. We revisit the electronic structure properties of ZnO-GaN systems using an evolutionary algorithm designed for crystal structure prediction coupled with ab initio calculations. An orthorhombic GaN-ZnO crystal phase, with space group Pmc21 (no. 26), was uncovered. The thermodynamic stability analysis reveals that while the Pmc21 crystal is not stable against phase separation, GaN-ZnO has low formation enthalpy of ~30 meV/atom and a relatively moderate miscibility temperature of ~461°C. The calculated phonon structure shows that GaZnNO is dynamically stable. The derived direct bandgap (Γ→Γ) value of 1.875 eV could be exploited in solar cell applications, providing high efficiency of ~25% for a thickness of ~0.5 μm based on the metric of spectroscopic limited maximum efficiency. The valence band maximum at the Γ point shows strong antibonding Zn(d)-N(p) character. The Zn(d)-N(p) repulsion mechanism reduces the direct band by almost ~2 eV. Moreover, we find a huge optical bandgap bowing of 6.3 eV. Our calculations indicate that atomic displacements induce dynamical charges of large amplitude and are the key factors favoring strong bandgap variation and extreme bandgap bowing parameters.

Layered perovskite structured Re5Ti4CrO17 (Re = La, Nd) ceramics were synthesized via a sol–gel method. Rietveld analysis and Raman spectroscopy showed that the samples crystallize into an orthorhombic crystal structure with the space group Pmnn. The samples showed a dense and homogeneous microstructure when sintered at 1600 °C for 4 h and the grain size was found to be 2.64–4.93 μm. La5Ti4CrO17 and Nd5Ti4CrO17 exhibited dielectric constant (er) ~ 23 and 12 at 1 MHz, respectively, which was dependent on the dielectric polarizability and bond lengths. Dielectric loss at room temperature was found to be ≤ 0.05 (at 1 MHz) for La5Ti4CrO17 and Nd5Ti4CrO17, respectively. Furthermore, magnetic study of the samples showed a paramagnetic behavior.

For the investigation of the exchange bias effect and magneto-optical properties of Bi0.8Re0.2(Re = Nd and Sm)FeO3 (BNFO and BSFO) nanofibers were synthesized via the electrospinning technique. The crystal structure was changed from rhombohedral phases of space group R3c before undoping shift to orthorhombic phases of space group Pbam and Pnma after doping of Nd3+ and Sm3+ ions, respectively, by the Rietveld refinement results. Analysis of the magnetic hysteresis loops demonstrated that the remanent magnetization especially coercivity of BNFO and BSFO nanofibers at 10 K and 300 K exhibited obviously variation, which was attributed to the lower temperature suppressed the fluctuation of magneto-caloric and valence state. The XPS and EDS results displayed the Nd3+ and Sm3+ ions were successfully doped into BFO nanofibers. Meanwhile, the lattice distortion induced the suppression of antiferromagnetic ordered spin modulation, which played an important role to enhance the magnetic properties. It was observed that the exchange bias effect (HEB) of BNFO nanofibers was higher than those of BSFO nanofibers. UV–vis spectra measurements revealed the band gap of BNFO and BSFO nanofibers was 1.87 eV and 1.85 eV, respectively, and the absorption edges of BSFO nanofibers occurred a slightly red shift. The MO degradation rates of BNFO and BSFO nanofibers reached about 89.4% and 78.6%, respectively, which could be a potential candidate in photo-electron devices and the semiconductor industry.

In this work, five substituted perovskite such as (Gd0.9Sr0.1) Mn0.8Co0.2O3, Tb0.8Sr0.2FeO3, Gd0.6Sr0.4RuO3, SrCe0.95Y0.05O3, and Mn0.6Co0.4SnO3 were synthesized by tartrate and hydroxide precursor method. The resulting samples were characterized by inductively coupled plasma spectroscopy, energy dispersive X-ray analysis, infrared spectroscopy, thermal analysis, X-ray powder diffraction, transmission electron microscope (TEM), selected field of electron diffraction (SAED), d.c. electrical conductivity, Hall effect, dielectric measurements, and low-temperature magnetization measurements. The X-ray diffraction pattern for all compounds was indicated the formation of single-phase perovskite with orthorhombic structure except Tb0.8Sr0.2FeO3 and Mn0.6Co0.4SnO3 perovskite. These compounds showed a cubic and rhombohedral structure, respectively. The lattice parameter and the unit cell volume slightly decreased as ionic radii decrease in agreement with the lanthanide contraction. The average size of cation ˂ RA ˃, mismatch factor (σ2), and tolerance factor (t) gives the combined effects of disorder and inhomogeneity in these compounds. The average particle size determined from TEM was in the range of 22 to 77 nm for all compounds. The temperature dependence of electrical conductivity for all compounds showed a definite break in 500 K to 610 K. except the Gd0.6Sr0.4RuO3 compound, which corresponds to semiconducting behavior. While the Gd0.6Sr0.4RuO3 sample shows a metallic-like semiconductor. The thermoelectric power and Hall effect measurements for all compounds were n-type semiconductivity except the SrCe0.95Y0.05O3 compound. It showed p-type semiconductivity. The frequency dependence of the dielectric constant and dielectric loss in these substituted perovskites were discussed using the Maxwell-Wagner model. Magnetic studies showed that the thermo-magnetic irreversibility for all compounds.

The structural and electronic properties of orthorhombic methyl ammonium lead iodide (CH3NH3PbI3 ) were investigated using the first principles density functional theory within the local density approximation (LDA) and the generalized gradient approximation (GGA).The lattice parameters obtained using the GGA were slightly greater than that obtained using the LDA. The total density of states and the electronic structure of the compound show that it is a direct band gap semiconductor. Our results are in agreement with the previous experimental and theoretical results and suggests that orthorhombic CH3NH3PbI3 compound is very promising in photovoltaic energy harvesting.

In this work, Li2Mg2[WxMo(1−x)O4]3 (i.e., 0 ≤ x ≤ 1) ceramics with high Q×f values were successfully fabricated at low temperatures (i.e., ≤ 950°C). The sintered specimens were found to exhibit of a single orthorhombic phase when x ≤ 0.6, whereas a secondary phase of MgWO4 was detected in the specimens when x ≥ 0.8. The ceramic samples exhibited homogenous microstructures and relatively high densities (i.e., > 90%) . In the sample with x = 0.2, outstanding microwave dielectric properties of er = 8.05, Q×f = 50,780 GHz, and τf = −73.6 ppm/°C were achieved at the sintering temperature of 825°C. Furthermore, no apparent reaction between a Ag electrode and the ceramic matrix was observed during the sintering process. As a result, Li2Mg2[WxMo(1−x)O4]3 ceramics proved to be promising candidate materials for low temperature co-fired ceramic (LTCC) technology.

The effects of a uniform and biaxial strain on the electronic structure of wide-bandgap orthorhombic Ga2O3 are studied using density-functional theory with the generalized gradient approximation (GGA) and the meta-GGA. Under uniform strain, as the strain increases, the lattice constants of the system decrease and the bandgap increases. However, under epitaxial strain, the bandgap increases with increasing compressive strain up to a certain level, and further increasing the compressive strain decreases the bandgap. This phenomenon is closely related to Poisson's ratio and increases of the lattice constant along the c-axis, which is not constrained by the epitaxial strain.

For the first time, AA h boron nitride (BN) crystal, assigned to an orthorhombic space group (No. 31, Pm21), is reported. The structure of BN nanotubes is reinterpreted as a helix, resulting from texture and helical growth of the AA h BN crystal used., AA h boron nitride (BN) crystal, assigned to an orthorhombic space group (No. 31, Pm21), is reported here. This new AA h BN crystal exhibits a ‘linear’ morphology for high-resolution transmission electron microscopy (HRTEM) and a (non-hexagonal) ‘diagonal’ electron-diffraction pattern, which have been experimentally demonstrated in this article. It is also demonstrated that this new crystal is the basic structure of multi-walled BN nanotubes (BNNTs) existing in the form of a helix. The helical AA h BNNTs exist in a metastable phase owing to 〈200〉 texture growth of the orthorhombic crystal, where the energy is ∼15 meV higher than that of stable AB or AA′ BN. It is shown that the typical scanning electron microscope ‘fluffy cotton-like’ morphology of BNNTs is due to secondary growth of diverse BN sheets (including mono-layers) on incoherently scrolled wall strands of BNNTs, providing further evidence for the helical structure with HRTEM evidence for a left-handed helix.

Thermally and chemically stable perovskite-like layer structures have attracted extensively in the field of energy and environmental applications. In this study, La2Ti2O7 was synthesized by the solvothermal method at 180 °C. This method provides high pure and homogeneously dispersed nanorods of orthorhombic phase having length of 250 nm and width of 70 nm. Even though this is a low-temperature synthesis method, it yields high crystalline nature after calcination. The novelty of this work is its synthesis methodology by the solvothermal route to achieve lower weight loss of La2Ti2O7. Furthermore, they exhibit narrow absorption in the UV-region from 200 to 350 nm, makes it possible to fabricate it as UV photodetector at ambient condition. In presence of UV illumination at 390 nm, it shows sharp photocurrent response with the decay time of 1.7 s.

0.675BiFeO3-0.3BaTiO3-0.025LaFeO3-x mol% Nb2O5 (x = 0–1.25) multiferroic lead- free ceramics, fabricated by conventional solid-state reaction, were studied to reveal the effects of Nb2O5 on the structural, morphology, dielectric, ferroelectric, magnetic and magnetoelectric properties of the BiFeO3-based ceramics. After the addition of Nb2O5, the crystal structure of as-prepared samples remained orthorhombic phase. The doping Nb5+ ion could be able to inhibit grain growth remarkably and suppress the creation of oxygen vacancies of this ceramics, which resulted in the improvement of electrical insulation by two orders of magnitude. The ferromagnetism was apparently enhanced with increasing content of Nb2O5, and the observed remanent magnetization Mr peaked at 0.022 emu/g for x = 1. Suitable amount of Nb2O5 could be beneficial to the dielectric properties, with the optimal x at 0.75, with dielectric constant er of 918 at 100 Hz. The observed magnetoelectric coefficient αME suggested the existence of magnetoelectric coupling effect in these ceramics. The αME value almost decreased after adding Nb2O5, possibly due to the obvious degradation of ferroelectric behaviors.

(Cu0.5Tl0.5)(Ba2–yCay)(CaMg)(Cu3–xZnx)O10–δ (y = 0, 1; x = 0, 2, 2.5, 2.8, 3) and (MxTl1–x)(BaCa)(CaMg) Zn3O10–δ (M = Ag, K; x = 0, 0.5) superconductors are synthesized for the studies of role of spin density waves in the mechanism of high Tc superconductivity. Such compounds are synthesized by reducing the thickness of the charge reservoir layers and distance among various CuO2/ZnO2 planes; decreasing the thickness of charge reservoir layers (CRLs) and distance among the various CuO2/ZnO2 planes increase the spin–spin interaction. All such samples were prepared by a two-step solid-state reaction (SSR) method at 860 °C and have shown orthorhombic crystal structure in which volume (V) of the unit cell suppresses with the doping of Ca, showing that partial substitution of Ca at the Ba site suppresses the thickness of CRL that in turn promotes a decrease in c-axis length and volume of the unit cell. The phonon modes related to the vibrations of apical and planar oxygen atoms are softened with doping of Ca and Zn in the final compounds. Metallic variations of resistivity (ρ) from room temperature down to the onset of superconductivity are a typical feature of these samples in which the Tc(onset) and Tc(R = 0) suppress with the doping of Ca, Mg, and Zn in the final compounds. Surprisingly, the samples with all the CuO2 planes replaced by ZnO2 planes have shown superconducting properties. To confirm the role of Cu(3d9) atoms in superconductivity, we have synthesized (MxTl1–x)(BaCa)(CaMg) Zn3O10–δ (M = Ag, K; x = 0, 0.5) samples. To our surprise, such samples have shown semiconducting behavior and no sign of superconductivity down to 77 K which demonstrated that the presence of Cu(3d9) atoms either in CRLs or ZnO2 planes is essential for the mechanism of high Tc superconductivity. These studies have shown the unequivocal role of small spin-carrying Cu-atoms in the mechanism of high Tc superconductivity. Fluctuating spins of Cu(3d9) atoms in the CuO2 plane generate spin waves, and hence, their interaction with charge density waves develop long-range phase coherence among the carriers that result in high-temperature superconductivity in oxides.

This manuscript is discussing the growth of a new class semi-organic nonlinear crystal l-Lysine hydrogen chloride (LLHC) was grown by slow evaporation method using a mixed solvent of deionized water + ethanol and pure deionized water. The crystal crystallizes in orthorhombic space group of P212121. Lattice parameters were revealed by single crystal X-ray diffraction analysis. The FT-IR spectral analysis was performed on the grown crystal LLHC to identify its functional groups. The position of protons and carbons was determined by the NMR technique. The grown crystal was characterized by optical transparency through UV–Vis range with a short cutoff wavelength of 212nm. Thermal and physiochemical stability of the title crystal was found out through the TG-DTA analysis, which proves the crystal stability up to 251.4 °C. Brewster’s point method was used to find out the refractive index of the grown compound LLHC. Vickers’s microhardness test was performed on LLHC to find out its mechanical stability. The second harmonic generation (SHG) of the grown crystal LLHC was confirmed by the Kurtz-perry powder method and the SHG efficiency was compared with the known Potassium Dihydrogen phosphate (KDP) standard. By using a minimal bactericidal concentration (MBC) benchmark, their antibacterial activity was evaluated. The grown crystal shows long-term and outstanding antibacterial activity against E.coli and S.aureus.

Highly electroactive Zn-embedded Ni9S8 nanosphere and its ZnS/NixS6-based nanocomposites were prepared by a simple hydrothermal route. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectra (FTIR), high-resolution scanning electron microscope (HR-SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectral (EDX) techniques. The XRD analysis revealed the formation of orthorhombic phase of Zn-embedded Ni9S8 nanosphere for hydrothermally treated sample. The supercapacitance behavior of crystalline Zn-embedded Ni9S8 nanosphere and ZnS/NixS6 nanocomposite modified electrodes were investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques. Zn-embedded Ni9S8 nanosphere prepared by hydrothermal route achieved highest specific capacitance value of 145 F/g in 1 A/g compared to the calcined sample modified electrodes. The maximum capacity retention of 100, 96 and 90% at 2000 cycles @1 A/g were observed for the pristine Zn–Ni9S8 and calcined Zn-Ni9S8 at 200 and 300 °C, respectively.

The detailed comparison of the effects of Co and CoFe2O4 dopants and preparation methods (solid-state reaction method and sol–gel methods) have been studied on structural, electrical, superconducting, and mechanical properties of Y123 bulk superconductors. The doping amounts of Co and CoFe2O4 were chosen up to 0.10 wt. %. X-ray powder diffraction (XRD) method, temperature-dependent resistance measurement (R-T), and Vickers microhardness analyses were performed to characterize prepared samples. XRD analysis showed that all samples have Pmmm symmetry of orthorhombic crystal structure; intensities and width of the diffraction lines were affected by doping material, but, independent of the preparation method. Although all samples crystallize in orthorhombic structure and exhibit superconductivity behavior, with increasing doping rate the critical transition temperatures of the samples showed a significant decrease and broadened to superconducting temperature transition width. This is more evident in CoFe2O4-doped Y-123 samples produced by sol–gel method. As the applied force increased, it was observed that the microhardness values of the Co-doped samples increased while the CoFe2O4-doped samples decreased, regardless of the sample preparation method.

The room temperature electrocaloric effect is researched for (110) oriented KNbO3 film based on Landau-Devonshire theory. The phase map with different ferroelectric states is built at room temperature with the considerations of thermodynamic equilibrium conditions and minimum of thermodynamic potential. Five ferroelectric structural phases are obtained theoretically. The negative in-plane misfit strains are conducive to form the tetragonal c phase and the positive strains are in favor of the stability of tetragonal a1 and a2 phases. The electrocaloric effect relies on both misfit strain and electric field. Moreover, large electrocaloric effect is achieved in the orthorhombic phases.

The crystal and electronic structure properties of Ni-B (nickel-boron) alloy coatings produced by an electrodeposition method have been investigated. The crystal structures of the alloy coatings were determined by x-ray diffraction patterns and supported by extended x-ray absorption fine structure (EXAFS) spectroscopy. The local atomic structure around the Ni atom was obtained from EXAFS studies at the Ni K-edge, and the EXAFS data were fitted with theoretical calculations. With the addition of boron atoms in the nickel environment, NiB composite alloys were formed in the crystals with an orthorhombic "Cmcm" structure. The analysis revealed a limited effect of boron doping in the electronic structure of the nickel atoms. Boron atoms were determined as sitting between the Ni atoms and causing a disturbance in the crystal structure due to providing inhomogeneous interstitial potential and defects.

High-performance alloy materials are increasingly considered for various engineering applications due to their combination of desirable properties. However, the guided wave-based structural health monitoring of alloys is often challenged by their strong anisotropic nature, which makes it difficult to calculate the guided wave behavior and associate mode shapes. In this article, Lamb mode waves of Cu–Al–Ni alloy under uniaxial stresses are characterized by developing a novel numerical polynomial approach, which may provide an efficient way to solve problems concerning acoustic wave propagations. To facilitate understanding of the dispersion curve trajectories, the anisotropic phase transformation from cubic phase (austenite) to orthorhombic plate (martensite) is considered. The comparison of the evanescent mode trajectories between the cubic and orthorhombic alloys shows the presence of imaginary modes in the cubic phase, although they may not exist in the orthorhombic phase at specific frequencies. In the case of Lamb propagation in the cubic alloy, the dispersion curves oscillate strongly, creating crossings among multiple symmetric and antisymmetric modes. This study also concerns the second harmonic generation of Lamb mode pairs in cubic and orthorhombic alloys. Furthermore, effect of uniaxial stresses on Lamb dispersion curves in both phases are also identified and discussed. The results obtained may promote understanding and optimization of novel acoustic devices made of anisotropic materials.

Eleven examples of hexagonal and orthorhombic polymorphs of intermetallic compounds having 5:3 stoichiometry are listed in the International Crystal Structure Database. A transition temperature between them has only been determined for the Yb–Sb and Sr–Bi systems, but results on the Sr–Bi system are discrepant with those on the Yb–Sb system, in which the phase relationships are well constrained by experimental data, for example, that the lower-temperature polymorph is the prototype orthorhombic Yb5Sb3 structure (αY5Sb3) and the higher temperature polymorph (βYb5Sb3) is isostructural with hexagonal Mn5Si3, with the transformation occurring at 1280 °C. In contrast, thermodynamic modeling on the Sr–Bi system give the inverse sequence of polymorphs with increasing temperature. It appears unlikely that the hexagonal Mn5Si3 structure type can be stable at higher temperatures than the orthorhombic Yb5Sb3 structure in one system, while orthorhombic Yb5Sb3 structure is the stable phase at higher temperatures in another system. The discrepancy can be attributed to the limited experimental data used to model the phase relationships in the Sr–Bi system.

The present article is focused to probe guanidinium benzene-1,2-dicarboxylate (GUBD) crystal synthesized by slow evaporation technique. The synthesized material possesses centrosymmetric structure with Pbcn space group having orthorhombic crystal system. The inter-contacts of the synthesized material have been investigated using Hirshfeld surface analysis and it clearly visualizes that the intermolecular hydrogen bonding takes place for structural stabilization. The functional groups of synthesized material have been affirmed from FT-IR and FT-Raman spectra. GUBD possess cut-off edge at 250 and 272 nm with high optical transparency in the visible-NIR region. The T/G and DTA show studied compound is thermally stable up to 300 °C. The observation of maximum intensity peak for the GUBD crystal at 570 nm pointed out green fluorescence emission. The Vicker’s hardness analysis reveals reverse indentation size effect. Dielectric studies of the GUBD crystal were measured. The nonlinear optical measurements on GUBD material confirm the two-photon absorption with reverse saturable absorption behavior and the crystal is potentially sufficient for optical limiting-based laser safety devices. The antibacterial activities of GUBD crystal against strains Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus have been analyzed. Furthermore, the grown GUBD crystal finds potential application in the field of electro-optic device and pharmaceutical applications.

Perovskite structured materials have received a lot of attention recently due to their extraordinary characteristics. In this work, conventional solid-state reaction was adopted to synthesize perovskite-based lanthanum ferrite materials and studied their inherent properties with the influence of Mn concentrations. The materials were characterized by XRD, FTIR, Raman, SEM, EDS and mapping, UV–Vis, photoluminescence, dielectric, magnetic properties and the Mn ions were found to be incorporated into the lanthanum ferrite. Rietveld refinement results confirm that synthesized materials are single-phase orthorhombic structures with an average crystallite size of 80–67 nm. A broad excitation band around 360 to 450 nm with a maximum at 409 nm is attributed to the intra configurational f–f electronic transition of La3+. Mn-doping-induced great enhancement in the visible range of LaFeO3 red luminescence. Mn-dopant has a significant influence on dielectric characteristics in the frequency ranges of 1 kHz and 1 MHz from 50 to 110 °C, which obey the Maxwell–Wagner polarization model and Koop's phenomenological theory. The observation of weak ferromagnetism at 305 K in the M–H loop is considered to be the result of the intriguing exchange interaction between Fe/Mn and oxidation states. It is proposed that LaMnxFe1−xO3 (x = 0.05–0.25) materials with varying characteristics could be developed to satisfy a diversity of requirements.

In this work, we report the sol–gel spin-coated novel thin film Aurivillius Phase Layered Bismuth titanate (Bi4Ti3O12, BTO) thin film coated on FTO glass substrate annealed at 700 °C was prepared and its detection of mercury ion. The structural orientation, surface morphology, chemical composition, vibrational, and optical properties of the prepared thin film were characterized using XRD, SEM, XPS, Raman, UV–Vis, and PL, respectively. From the XRD analysis, the crystal growth is well preferred in (117) plane corresponding to the orthorhombic structure of BTO. SEM images of the prepared thin film exhibited an anisotropic plate-like grained structure. Photoluminescence spectra showed a good optical emission peak at 545 nm. In Raman spectra, the observed phonon modes are well correlated to the orthorhombic phase of BTO thin films. XPS confirmed the oxidation states of Bi4Ti3O12 thin film. The electrocatalytic activity of the prepared BTO thin film electrode concerns mercury detection using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) technique. CV analysis disclosed that the prepared thin film electrode is very active in the electrochemical performance of heavy metal (Hg) detection. LSV result reveals that the prepared thin film exhibits enhanced sensitivity and lower detection limit of electrochemical Hg detection. From the electro-oxidation studies, the BTO thin film electrode acts as a favorable candidate for the application of heavy metal detection.

Effects of Ga substitutions in R2Al1-xGax (R = Gd, Er) alloys have been studied. Gd2Al1-xGax (x ≤ 0.2) and Er2Al1-yGay (y ≤ 0.3) alloys are found to be crystallized in Co2Si-type orthorhombic structure. With increased Ga substitution for Al, the phase transition temperature is gradually increased. For the field change of 7 T, the maximum of entropy change (-ΔSM) is increased to 14.8 J/kgK and 11.2 J/kgK in Gd2Al0.8Ga0.2 and Er2Al0.7Ga0.3 alloys compared with 11.4 J/kgK and 8.3 J/kgK of Gd2Al and Er2Al alloys. And the relative cooling power is nearly doubled to 699.6 J/kg in Gd2Al0.8Ga0.2 alloy. As increasing Ga substitution, the critical magnetic field for the transition is decreased in Gd2Al1-xGax (x ≤ 0.2) alloys, and the magnetization is increased in Er2Al1-yGay (y ≤ 0.3) alloys. The considerable ΔSM implies that those materials are promising candidates for magnetic cooling.

An X-ray diffraction study aimed at establishing the subtle details of the electron density and anharmonicity of the atomic vibrations in a stoichiometric monodomain single crystal of potassium niobate, KNbO3, has been conducted at room temperature (orthorhombic ferroelectric phase Amm2). The cation and anion displacements obtained from the experiment are weakly anharmonic without any manifestation of structural disorder. The chemical bond and interatomic interactions inside and between crystal substructures at the balance of intracrystalline forces are characterized in detail. The role of each of the ions in the formation of the ferroelectric phase was studied and the features of the electron-density deformation in the niobium and oxygen substructures, and the role of each of them in the occurrence of spontaneous polarization are established. The position-space distribution of electrostatic and quantum forces in KNbO3 is restored. It is emphasized that for the completeness of the analysis of the nature of the ferroelectric properties it is necessary to consider both static and kinetic electronic factors, which are of a quantum origin. The experimental results and theoretical estimations by the Kohn–Sham calculation with periodic boundary conditions are in reasonable agreement, thus indicating the physical significance of the findings of this study.

High-quality nanometric and homogeneous particles of Cu–doped PrCrO3 ceramic compounds were synthesized by the hydrothermal-assisted sol–gel method. Structural, chemical state, morphology, and magnetic properties were investigated in the PrCr1−xCuxO3 orthochromite with 0 ≤ x ≤ 0.1 composition. XRD patterns show a complete solubility of the Cu ion, as well as an increase of the orthorhombic cell volume. The microstructural analysis (SEM) shows that the nanometric-size particles obtained from the synthesis process coalesce during the subsequent high-temperature process. In addition, XPS analysis revealed that the solubility and charge compensations by aliovalent Cu2+ ions substitution are driven by the change of the oxidation state from Cr3+ to Cr5+ and Cr6+. These results produce novel changes in the magnetic properties. There, the ZFC-mode shows negative magnetization in all investigated samples, and it is discussed as an intrinsic phenomenon in terms of the Γ2 (Fx, Cy, Gz) spin configuration as well as the arising of the diamagnetic Cr6+ (do). It is noted that Cr6+ tunes the diamagnetic magnitude during the ZFC protocol. On the other hand, different oxidation states are observed at the Cr site in PrCrO3, whose final result is an increase of the coercivity field, Hc, and the remanent magnetization, Mr, in the M–H curves. The increase of ferromagnetic and the antiferromagnetic domains sharing the same volume leads to an anisotropic magnetic interaction, called exchange-bias effect. It is observed that the Cu-doped PrCrO3 decreases the exchange-bias effect, but at the same time an increase in the magnetic properties is observed at 2 K.

This paper deals with the study of the physical properties of ZnO/ZnNb2O6/Nb2O5 composite. X-ray diffraction (XRD) proves the coexistence of hexagonal ZnO, tetragonal Nb2O5 and orthorhombic ZnNb2O6. Scanning electron microscopy (SEM) observations reveals heterogenic distribution of grains with average size of about 456 nm. The dielectric measurements are performed in 20 Hz–1MHz frequency range between 150 °C and 350 °C. Theoretical fit demonstrates that the electric resistivity, associated to grains and grain boundaries, decreases as a function of temperature up to 275 °C. At 275 °C, the composite presents a semiconductor-metal transition, confirmed by the temperature-dependence of DC conductivity. Moreover, the AC conductivity variations suggest that the AC conduction mechanisms are explained by the Quantum-Mechanical Tunneling (QMT) model below 275 °C and the Non-Overlapping Small Polaron Tunneling (NSPT) one above 275 °C. Also, the activation energies, related to dielectric relaxation processes and DC conductivity, are almost equal: Ea ~ 0.53eV in the interval 150 °C 275 °C. Moreover, the permittivity variations show the existence of interfacial Maxwell-Wagner-Sillars (MWS) and dipolar polarization.

The variation of dielectric, ferroelectric and piezoelectric characteristics of BaZrO3–modified (Ba0.85Ca0.15)TiO3 ceramics, (1-x)(Ba0.85Ca0.15)TiO3-xBaZrO3, have been investigated together with the structure evolution. The crystal structure at room-temperature varies from tetragonal to metrically cubic through orthorhombic and rhombohedral, and the morphotropic phase boundary (MPB) is determined around x = 0.12 where the significantly enhanced dielectric, ferroelectric and piezoelectric characteristics are achieved. With increasing x, the present ceramics indicate the crossover from normal to diffused and relaxor ferroelectric, and the evolution process is explored systematically.

The doped LaGaO3 is a well-known intermediate-temperature electrolyte due to its high ionic conductivity and negligible electronic conductivity. However, the phase pure La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM 9182) compound is not easy to be prepared because of its sensitive character with preparing process. In this work, the influence of evaporating temperature (glycine-nitrate combustion method) on the phase formation and physical property of LSGM 9182 is investigated systematically. The samples with different evaporating temperature 80 °C ≤ T ˂ 84 °C, 84 °C ≤ T ˂ 88 °C, 88 °C ≤ T ˂ 92 °C and T ≥ 92 °C was named as compound A, B, C and D. XRD results show that the phase pure compound can only be synthesized with the evaporating temperature 80 °C ≤ T ˂ 84 °C, the higher evaporating temperature, the higher content of LaSrGaO4 or LaSrGa3O7 impurity. Due to the slight change in composition, shoulders and splitting of some XRD reflections in phase pure compound A disappear for compound D, representing an transition from low-symmetry orthorhombic lattice to high-symmetry cubic lattice. Owing to the competiting contribution between crystal symmetry and impurity, the conductivity of compound D does not decrease almostly at low temperature, however, the influence of low conductive LaSrGaO4 prevails at high temperature, consequently, the conductivity of compound D decreases to a large degree at 800 °C. Above results suggest that evaporating temperature is an important parameter to prepare high quality LSGM electrolyte, suitable evaporating temperature supplies proper energy for chemical reaction and produce single perovskite phase compound finally.

This paper presents the results of a study of the structural, optical, and photocatalytic properties of ceramics based on ATiO3 titanates, A = Ca, Sr, Ba. Using the method of X-ray phase analysis, it was found that in the case of ceramics obtained from a mixture of BaCO3 and TiO2 after annealing, the structure is a mixture of two phases, rhombohedral BaTiO3 and impurity orthorhombic BaTi4O9. In the case of ceramics obtained from a mixture of CaCO3 and TiO2, the structure is a mixture of two phases of the orthorhombic phase and rutile TiO2. In the case of ceramics obtained from a mixture of SrCO3 and TiO2, the structure is a mixture of two phases of the SrTiO3 orthorhombic phase and the Ti2O5 orthorhombic phase. At the same time, all synthesized ceramics have a high crystallinity degree and order of the crystal structure. An analysis of the optical properties showed that the main changes are associated with the difference in the band gap, which is due to the presence of different phases in the structure of ceramics. Based on the results of photocatalytic reactions, the order of photocatalytic activity of the synthesized ceramics was determined: SrTO3/T2O5 > CaTO3/TO2 > BaTO3.

In an elastic model with orthorhombic (ORT) symmetry, there are nine independent stiffness coefficients that control the propagation of all intrinsically coupled wave modes. For practical applications in P-wave modeling and inversion, it is important to derive the approximate solutions that support propagation of P-waves only and depend on fewer independent parameters. Due to the increasing interest in S-wave propagation in anisotropic media, we also derive an approximate equation that supports propagation of S-waves only. However, the reduction in the number of independent parameters for the S-wave equation is not possible. We derive pure P- and S-wave equations in an elastic ORT model and find that the accuracy is sufficient for practical applications.

Because of their particular characteristics, searching for potential sp2–sp3 hybridized carbon allotropes has become the foundation of new functional materials in the future. Here, we design a novel carbon phase constructed by sp2–sp3 hybridized bonding networks with a 36-atom body-centered orthorhombic unit cell, termed oC36. oC36 shows thermodynamic stability comparable to most of the theoretically predicted sp3 carbons. The elastic and dynamical stability of oC36 is confirmed by the calculation results of elastic constants and phonon spectra. Analysis of electronic properties reveals that oC36 changes from semiconductivity to one-dimensional conductivity with external pressure exceeding approximately 4 GPa. The conductivity arises from the overlap of the valance and conduction bands owing to sp2 hybridized nonbonding carbon interactions as the lattice constant decreases. Electron–phonon coupling calculations indicate the superconductivity of oC36 under 25 GPa, and its λ and TC values are 0.50 and 10.7 K, respectively. Strikingly, the estimated hardness, tensile strength, and shear strength of oC36 reach remarkably high values of 69.5, 79.1, and 78.9 GPa, respectively, indicating its superhardness and ultra-incompressibility. Our research expands the scope of sp2–sp3 carbon allotropes and provides new ideas for the later theoretical design of carbon allotropes with switchable properties.

Fayalite Fe2SiO4 is synthesized by the solid-state reaction without ball milling. The obtained powder is further structurally and electrochemically examined. Field emission scanning electron microscopy (FESEM) showed that microsized powder is obtained. X-ray powder diffraction (XRD) pattern is used for both phase identification and crystal structure Rietveld refinement. The structure is refined in the orthorhombic Pbnm space group. Mössbauer spectroscopy revealed traces of Fe3+ impurity. The bond valence mapping method is applied for the first time on Fe2SiO4 framework. It shows isolated, non-connected isosurfaces of constant E(Li), which further supports the assumptions of the conversion reactions. Electrochemical performances are investigated through galvanostatic cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). Ex-situ XRD and Fourier transform infrared spectroscopy (FTIR) analyses are combined to monitor phase change after galvanostatic cycling and to reveal the working mechanism during electrochemical lithiation. This is the peer-reviewed version of the article: Jugović, Dragana, Milović, Miloš, Ivanovski, Valentin N., Škapin, Srečo, Barudžija, Tanja, Mitrić, Miodrag, "Microsized fayalite Fe2SiO4 as anode material: the structure, electrochemical properties and working mechanism" in Journal of Electroceramics (2021), [https://doi.org/10.1007/s10832-021-00260-9]

In the search for new high-temperature superconductors, it has been proposed that there are strong similarities between the fluoroargentate AgF2 and the cuprate La2 CuO4 . We explored the origin of the possible layered structure of AgF2 by studying its parent high-symmetry phase and comparing these results with those of a seemingly analogous cuprate, CuF2 . Our findings first stress the large differences between CuF2 and AgF2 . Indeed, the parent structure of AgF2 is found to be cubic, naturally devoid of any layering, even though Ag2+ ions occupy trigonal sites that, nevertheless, allow the existence of a Jahn-Teller effect. The observed Pbca orthorhombic phase is found when the system is cooperatively distorted by a local E⊗e trigonal Jahn-Teller effect around the silver sites that creates both geometrical and magnetic layering. While the distortion implies that two Ag2+ -F- bonds increase their distance by 15 % and become softer, our simulations indicate that covalent bonding and interlayer electron hopping is strong, unlike the situation in cuprate superconductors, and that, in fact, exfoliation of individual planes might be a harder task than previously suggested. As a salient feature, these results prove that the actual magnetic structure in AgF2 is a direct consequence of vibronic contributions involved in the Jahn-Teller effect. Finally, our findings show that, due to the multiple minima intrinsic to the Jahn-Teller energy surface, the system is ferroelastic, a property that is strongly coupled to magnetism in this argentate.

Pure V2O5 and MnO2/V2O5 hybrid nanocomposites were synthesized by microwave-assisted method for electrochemical supercapacitor application. X-ray diffraction analysis showed the orthorhombic structure for pure V2O5 and MnO2/V2O5 nanocomposites that showed the mixed state of the orthorhombic and orthogonal phase structure of V2O5 and MnO2. The average crystalline sizes were calculated as 14 nm and 17 nm for pure V2O5 and MnO2/V2O5 nanocomposites. Scanning electron microscopy and Field emission scanning electron microscopy image analysis demonstrated the mixed state of nanoplate and small rod-like shape for V2O5 and it was transformed to nanobeads shape by the addition of MnO2. The Energy Dispersive X-Ray Analysis confirmed the presence of V and Mn compounds in the as-prepared nanocomposites. The porous nature of nanostructures was studied by Brunauer–Emmett–Teller analysis. Finally, the electrochemical analysis was recorded in 3.5 M KOH and 1 M H2SO4 electrolytes to compare its performance and suitability. The pure V2O5 nanostructure showed the maximum capacitance of 150 F/g and 95 F/g in KOH and H2SO4 electrolytes. The specific capacitance of V2O5 was enhanced to 570 F/g for the addition of 6 wt% of MnO2 in 3.5 M KOH electrolyte, whereas, in 1 M H2SO4 electrolyte, the specific capacitance was 269 F/g for the addition of 6 wt% of MnO2.

High transparent lead-free (1−x)K0.5Na0.5NbO3-xSr(Yb0.5Ta0.5)O3 (KNN-xSYbT, x = 0.005, 0.01, 0.02, 0.03, 0.04, 0.05) ferroelectric ceramics were synthesized by the conventional solid-phase sintering method. The effects of Sr(Yb0.5Ta0.5)O3 doping on the microstructure, phase transition, optical and electrical properties were investigated. At x = 0.01, an excellent transmittances of 52.3% in the visible region and 68.2% in the infrared region was achieved, and the optical bandgap Eg was 3.00 eV. X-ray diffraction indicates that the crystal structure of the ceramics transformed from orthorhombic phase to pseudo-cubic phase with doping of Sr(Yb0.5Ta0.5)O3. After introduction of Sr(Yb0.5Ta0.5)O3, the grain size of the ceramics changes obviously and the grains become smaller gradually. The ceramics with x = 0.01 exhibited the optimal energy storage properties with Wrec = 0.55 J/cm3 and η = 61.1%. The maximum dielectric constant of 3300 was obtained at x = 0.005. The results illustrated that the proposed system has a broad application prospect in multi-functional integrated devices.

In this work, the very rapid one-step mechanochemical synthesis of nanocrystalline ternary chalcogenide chalcostibite CuSbS2 prepared from copper, antimony, and sulfur precursors by high-energy milling for only 30 min in a planetary mill is reported. XRD confirmed the orthorhombic crystal structure of CuSbS2. The crystallite size of CuSbS2 calculated by LeBail refinement of the X-ray powder diffraction data was 25 nm. The nanocrystalline chalcostibite CuSbS2 was also confirmed by transmission electron microscopy. The purity of CuSbS2 was verified by Raman spectroscopy. The synthesized chalcostibite exhibits the specific surface area value of 2.4 m2g−1. UV–Vis spectroscopy showed the optical bandgap of CuSbS2 as 1.54 eV with wide range of absorption in visible region. Photoresponse of CuSbS2 was confirmed by I–V measurements under dark and light illumination. The proposed mechanochemical synthesis provides an alternative approach to prepare also other ternary semiconductor nanomaterials. CuSbS2 semiconductor nanocrystals have the potential to be used as light absorbers in photovoltaics.

In this work, the RMO3 (R = Pr, Nd and M = Fe, Co) perovskites had been synthesized by hydrothermal method. The structural properties of RMO3 prepared samples were investigated by using X-ray diffraction (XRD) analysis. These prepared perovskites showed the orthorhombic structure with the Pbnm space group. The Williamson-Hall method was used for determining the size of crystallites (DW–H) and lattice strains (ε) of the samples. In addition, scanning electron microscopy (SEM) was used for investigating the morphology and for determining the sizes of RMO3 particles. For magnetic characterizations of the samples, vibrating sample magnetometer (VSM) and FC and ZFC measurements had been used. The Neel temperatures (TN) of R ions were determined at TN = 29, 8 and 9 K for PrFeO3, PrCoO3, and NdCoO3 perovskites, respectively. The spin reorientation temperature (TSR) of NdFeO3 had been displayed at T = 163 K during FC and ZFC protocols. Thereafter, the Curie–Weiss law had been used for calculating the CW temperatures (θCW) and Curie constants (C) of the all samples based on FC measurements data.

In recent days, the development of low-cost, sustainable, efficient electrode materials for energy storage applications is of great interest. Herewith, Cu-doped Ca(Ti0.9Fe0.1)O3-δ (Cu:CTF) double-perovskite electroceramic, heat-treated at diverse temperatures (800–1100 °C) were prepared using sol–gel technology. X-ray diffraction pattern confirmed the orthorhombic structure of the prepared Cu:CTF perovskites. Significant traces of TiO2, CuO vanishes at elevated temperatures, which is evident from the XRD pattern. Further, the secondary phase traces were also observed in XRD, but without changing its crystal structure of Cu:CTF nanotitanate. The crystalline nature of the Cu:CTF ceramic was identified around 750 °C employing TG/DTA. UV–visible spectroscopy demonstrates the poor visible absorbance region towards the red shift with the bandgap variation of 5.28–5.42 eV. The nature of the Cu:CTF particles were analyzed using electron microscopes with the estimated particle size between 52 and 190 nm. Considering the action of temperature and frequency, complex impedance spectroscopy was utilized to analyse the inter- and intra-grain inclusions. Complex impedance spectroscopy study confirms the existence of dipole–dipole relaxation and Maxwell–Wagner (MW) polarisation for the samples heated above 900 °C. However, the a.c. test reveals the presence of conduction due to the addition of Cu2+ ions to CaTi1-xFexO3-δ perovskite, which enhances oxygen vacancies and is strongly dependent on the inhibition of the hopping conduction mechanism.

Tin monosulfide can be grown in cubic (pi-SnS) and orthorhombic (alpha-SnS) polymorphs by low-temperature atomic layer deposition (ALD). The optical properties of these polymorphs make them attractive for the realization of plasmonic solar cells with ultrathin absorber layers down to 10 nm in thickness. SnS is also an earth-abundant and nontoxic compound semiconductor of high interest for regular thin-film photovoltaics. To better understand the behavior of the two SnS polymorphs in ultrathin solar cell configurations, we here fabricate, characterize, and analyze a range of such devices. ALD is used to grow SnS and form heterojunctions with zinc oxysulfide [Zn(O,S)], acting as a buffer layer with a composition-tunable bandgap. Apart from the roles of the SnS polymorph and Zn(O,S) composition, the effects of the back contact material and thicknesses of buffer and absorber layers are investigated. Devices using pi-SnS and pure ZnO buffers yield the highest photocurrents (3.1 mA/cm(2)) and higher open circuit voltage (159 mV) than similar alpha-SnS-based devices. Analysis of the equivalent-circuit parameters suggests that interface recombination limits the voltage for these devices. While Zn(O,S) with a higher sulfur content provides chemical passivation of the SnS interface and excessive open circuit voltages above 600 mV, it also exhibits a too high conduction band offset, which hampers current collection. A growth delay during the ALD of Zn(O,S) on SnS initially amplifies the known sulfur-oxygen exchange reaction, such that a sulfur-rich Zn(O,S) region forms next to the SnS interface. This causes a thin ZnS-like barrier to form already for low cycle fractions of the H2S precursor in the ALD super-cycle. Voltage and fill factor trends suggest an optimal SnS absorber layer thickness in the range of 15-35 nm, presenting an opportunity for plasmonic absorption enhancement. Devices with pi-SnS show most promise, but interface recombination versus current-blocking is a dilemma for the SnS/Zn(O,S) heterojunction.

4-dimethylaminopyridine lithium nitrate crystal (4-DMAPLN) was synthesized by the slow evaporation solution growth technique. The titular crystal was subjected to various studies to recognize its physicochemical properties. The crystalline nature and orthorhombic crystal system were revealed by single crystal and powder XRD. FTIR spectroscopy study confirms the various modes of vibrations available in the titular crystal. Linear optical studies show the lower cut-off wavelength of 280 nm with an optical bandgap value (Eg) of 4.3 eV. The electrical behavior of the 4-DMAPLN crystal was studied using dielectric studies. The mechanical behavior of the grown crystal was analyzed using the Vicker’s microhardness study, revealing that the grown crystal belongs to the hard category. The second-order nonlinear optical (NLO) behavior of 4-DMAPLN crystal was measured using Kurtz–Perry powder techniques and it was found to be 1.17 times higher than reference KDP. Z-scan analysis reveals 4-DMAPLN is a suitable candidate for optical limiting applications.

This paper reports the effect of chromium’s substitution in magnetic oxides with perovskite structure La0.5Sm0.2Sr0.3Mn1-xCrxO3 (x = 0, 0.1, 0.15 and 0.2) compounds which have been produced with the glycine-nitrate process (GNP). The four compounds have an orthorhombic crystal structure with ‘Pnma’ space group. We note that they undergo a second-order paramagnetic-ferromagnetic (PM-FM) phase transition. Substitution manganese by chromium leads to a drop of the Curie temperature TC from 278 K (x = 0) to 205 K (x = 0.2). Their magnetocaloric effect has been evaluated by their magnetic entropy change $$\left(-\Delta {S}_{M}^{max}\right)$$ under a magnetic field change up to 5 T. All relative cooling power (RCP) suggests that these compounds are suitable candidates for magnetic refrigeration.

A novel and good optical quality NLO single crystal of copper zinc hydrogen phosphate (CuZnHPO4) is grown by gel technique in silica hydrogel media. Both single crystal and powder X-ray diffraction analysis found that the orthorhombic crystal arrangement with space group Pnma and the predictable lattice parameters are a = 10.51 A, b = 18.9 A, c = 5.05 A, and α = β = γ = 905. Thermogravimetric analysis is used to perform this thermal stability of the crystals that have been produced. SEM and TEM images reveal that plate-like morphology and further plate-like growth were observed on some plates. UV spectra results reveal that the absorption of the grown crystal was found in the visible region and suggest that it can be useful for NLO applications. With increasing frequency, both the dielectric constant and the dielectric loss reduced. Moreover, the grown crystal had high conductivity and the activation energy of 0.426 eV. Photoconductivity studies of CuZnHPO4 revealed the positive photoconduction nature of the crystal. Kurtz–Perry powder SHG test was employed to determine the SHG efficiency. The estimated SHG efficiencies are 19.2 mJ and 52.6 mJ for KDP and CuZnHPO4 crystals, respectively. The results suggest that the SHG efficiency of CuZnHPO4 crystal is 2.73 times better than KDP single crystal.

We quantified the bulk Rashba splitting and suppression in polymorphs of MA(Pb, Sn, Ge, or Si)I3 perovskites. The low-computational-cost DFT-1/2 quasiparticle correction was performed for all structures, combined with the inclusion of spin-orbit coupling (SOC) effects. The presence of SOC and symmetry breaking from the metal off-centering octahedral distortion are indispensable and essential conditions for Rashba splitting, whose magnitude emerges from the Pb → Si sequence. Additionally, the quasiparticle correction provides energy bandgaps for MAPbI3 (cubic, tetragonal, and orthorhombic), MASnI3 (cubic and tetragonal), and MAGeI3 (cubic) that are in outstanding agreement with experimental results. However, while gap energies are yielded collaboratively from the metal off-centering and relative octahedral tiltings, the bulk Rashba suppression is reached for metal on-centering (octahedral platonic-like) configurations that are thermodynamically stable even when the charge polarization is kept invariant among metal-I bonds in the polymorphs.

The most generally used slow evaporation technique at ambient temperature is used to develop L-glutamine barium acetate (LGBA) materials for a variety of applications. The crystallinity, cell parameters (a = 16.22, b = 7.8 and c = 5.13), and space group (P212121) of the grown material are confirmed through X-Ray diffraction test and shows the grown material belongs to orthorhombic structure. The optical analysis clearly shows that LGBA crystals have higher transparency window from 233 to 800 nm, and Eg = 5.80 eV demonstrates the prepared crystals are suitable for optical applications. In addition, the important optical constants such as extinction coefficient, refractive indices, skin depth and optical conductivity are strongly depend on photon energy of the LGBA material indicating the phototunable nature of the material. The mechanical properties are validated with the aid of Vickers' microhardness measurement and it shows the work hardening coefficient of LGBA material and its value 3.7 which suggests the grown LGBA belongs to the class of soft material. Morphology of the grown material such as crystalline size, shape and purity is analyzed via SEM and HRTEM measurement. The SHG efficiency of the LGBA crystal grown is 1.33 times greater than that of the KDP crystal, because Ba+ ions strengthen the SHG efficiency of LGBA, as estimated by Kurtz and Perry's technique. Electrical results have documented the good conducting properties of LGBA crystal. The electrical study clearly identifies the grown crystal is less defective, good quality material because AC conductivity is high at high-frequency region. An antimicrobial assay validates that the LGBA substance is used to treat fungal and bacterial infections.

Lanthanum- and zirconium-doped perovskite Ba0.5Sr0.5Fe0.9Cu0.1O3-δ ceramics, i.e., LaBa0.5Sr0.5Fe1.8Cu0.2O6-δ (LBSFC) and Ba0.5Sr0.5Fe0.85Cu0.1Zr0.05O3-δ (BSFCZ), were synthesized and characterized. The characterizations include x-ray diffraction, scanning electron microscopy, x-ray near-edge absorption spectroscopy of the Fe K-edge and Cu K-edge, iodometric titration, and electrical conductivity measurements. The structure of BSFCZ was pseudo-cubic single perovskite, whereas LBSFC was orthorhombic double perovskite. It was also discovered that the iron and copper in the octahedron-site has a mixed oxidation state with iron having 3+/4+ and copper 2+/3+. The ratio of Fe3+/Fe4+ was found to be 59/41 for LBSFC and 75/25 for BSFCZ. Similarly, copper has a mixed Cu2+/Cu3+ = 24/76 for BSFCZ and 44/56 for LBSFC. The unit cell symmetry, the presence of La3+, and the formation of Fe4+/Cu3+ are thought to be responsible for the improvement in the electrical conductivity and performance of the LBSFC. In contrast, the Zr4- stabilized perovskite structure was unfavorable for electrical conductivity. The electrical performance of the LBSFC achieved a maximum conductivity σ = 150 S/cm-1 at 500°C.

In this report, Yb0.8Ca0.2MnO3, Dy0.8Ca0.2MnO3, and Nd0.8Ca0.2MnO3 perovskite compounds have been felicitously elaborated based on a fertile cost-effective solid-state reaction strategy. Dy0.8Ca0.2MnO3 and Nd0.8Ca0.2MnO3 powders were found to manifest orthorhombic structure, whereas the Yb0.8Ca0.2MnO3 sample was found to demonstrate hexagonal structure. However, the YbO2 secondary impurity phase was evinced with the perovskite Yb0.8Ca0.2MnO3 phase. The samples’ SEM images emerged with the uniform pseudo-cubic-like structure, and the grain sizes of the perovskite materials were in the range between 250 and 600 nm. FT-IR spectrums emphasized the band peaks linked with the functional group of the perovskite manganite compounds. Magnetic moment–magnetic field dependence features asserted antiferromagnetic characteristics for Yb0.8Ca0.2MnO3 and Dy0.8Ca0.2MnO3 samples, while the Nd0.8Ca0.2MnO3 sample disclosed paramagnetic phase at room temperature. Dielectric properties elucidated the normal behavior of perovskite at room temperature. This study explores the rule of the rear earth elements on tune the properties of perovskite compounds.

In this paper, the structural, electronic, elastic, mechanical, phonon and electron-phonon interaction properties of orthorhombic MoRuP have been analysed by using the generalised gradient approxim...