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Band gap engineering has been opening a way to enhance the performance of two-dimensional (2D) material devices. Here we report a synthesis of ternary MS 2(1−x) Se 2x (M = Mo, W) alloys with a band gap tunability of ∼170 meV using a solid state reaction method. X-ray photoelectron spectroscopy and Raman scattering characterizations reveal that the change of Se contents can be utilized to tune the composition of the ternary MS 2(1−x) Se 2x (M = Mo, W) alloys. UV–vis–NIR absorption results conform the realization of tunable band gap in MS 2(1−x) Se 2x (M = Mo, W) alloys tailored by different Se contents. The electrical transport investigation of the ternary alloys exhibits an n-type semiconductor behavior demonstrated by back-gated field effect transistors. [ABSTRACT FROM AUTHOR]

A series of TiN/Ni nanocomposite films with different Ni content were synthesized by reactive magnetron sputtering. The microstructural evolution, mechanical properties and strengthening mechanism of TiN/Ni nanocomposite film were studied. When Ni:Ti ratio is less than 1:24, the small amount of Ni can be dissolved in the TiN matrix, leading to the slight decrease of the hardness and elastic modulus. When Ni:Ti ratio rises to 4:21, Ni inclines to separate from TiN due to the thermodynamic incompatibility as an interfacial phase and grow coherently with adjacent TiN crystallites. As a result, the TiN/Ni film was remarkably strengthened with the maximal hardness and elastic modulus of 33.3 GPa and 373 GPa. As Ni:Ti ratio further increases to 5:20, Ni interface transforms into amorphous state, leading to the destruction of the epitaxial growth structure and the rapid decrease of hardness and elastic modulus. The strengthening effect of TiN/Ni nanocomposite film can be attributed to the coherent interface between Ni interfacial layers and TiN crystallites. [ABSTRACT FROM AUTHOR]

The hydrothermal electrochemical method was used to deposit hydroxyapatite coating on Ti6Al4V. In order to improve the bonding strength between the coating and substrate, the substrates were modified by 8 M NaOH solution before the deposition. The effects of immersing time on the substrate, on the hydroxyapatite coating, and on the bonding strength were studied. X-Ray Diffraction, Scanning Electron Microscope, Fourier Transform Infrared Spectroscopy and Drop Shape Analysis Method were applied. And the crystallinity of hydroxyapatite coating was calculated. The results show that immersing treatment effects the phase compositions, the microstructure and the wettability of the substrate surface. A porous, three-dimensional network structure is formed on the Ti6Al4V surface through the NaOH immersion. The pore size and depth increase with the increase of immersing time from 12 to 48 h. The surface microstructure of Ti6Al4V with 60 h′ immersion time was different from the others. The modification treatment can improve the bonding strength between hydroxyapatite coating and the substrate obviously. The value of the bonding strength with the substrate immersed for 48 h is larger than those of the others. A bone-like apatite layer forms on the coating after 3 days of soaking in SBF, implying with good bioactivity of the hydroxyapatite coatings deposited by the method. The surface characteristics of the sample immersed with 48 h are more conductive to the deposition of hydroxyapatite and to the improvement of the bonding strength. The formation mechanism of hydroxyapatite coating deposited by hydrothermal electrochemical method was discussed. [ABSTRACT FROM AUTHOR]

Through introducing the CrAlSiN modulation layers consisted of CrAlN and SiN x phases, a series of TiN/CrAlSiN nanomultilayered films with different Si content were synthesized by reactive magnetron sputtering. The effect of Si content on microstructural evolution and superhardness effect of TiN/CrAlSiN nanomultilayered film was investigated by XRD, HRTEM and nanoindentation techniques. When inserted by CrAlSiN nano-layers with Si:CrAl ratio less than 4:21, TiN layers can force CrAlSiN layers to transform into fcc structure and grow epitaxially with them, leading to appearance of the superhardness effect. The columnar crystal structure of TiN/CrAlSiN nanomultilayered film can be effectively refined by insertion of the CrAlSiN layers due to thermodynamic incompatibility of CrAlN and SiN x . As the Si content further increases, the amount of amorphous SiN x phase increases, which makes the CrAlSiN layers present amorphous feature and blocks the epitaxial growth structure within the TiN/CrAlSiN nanomultilayered film, resulting in the decrease of hardness and elastic modulus. [ABSTRACT FROM AUTHOR]

A silica nanotube scaffold with three-dimensional (3D) network structure for potential tissue engineering application was prepared via a scalable and eco-friendly template-assisted sol–gel process followed by calcination. Bacterial cellulose (BC) was used as both the template and the catalyst and the sol–gel process was conducted at ambient temperature and neutral pH. SEM, TEM, TGA, and the Brunauer–Emett–Teller (BET) surface area measurements were used to characterize the resultant silica nanotube scaffold. The as-prepared silica nanotubes are amorphous with distinct tubular structure and have an average outer diameter of less than 100 nm and a wall thickness of around 29 nm. The silica nanotube scaffold maintains the porous 3D network structure of BC template with numerous mesopores centered at 3.81 nm. Preliminary cell studies with L929 and MG-63 cell lines indicate that the silica nanotube scaffold supports cell attachment and spreading and shows excellent biocompatibility. These results demonstrate the potential application of the silica nanotube scaffold in bone tissue engineering and regeneration. [ABSTRACT FROM AUTHOR]

• Co 36 Fe 36 Cr 18 Ni 10 with a single-fcc structure large numbers of twins and SFs to effectively strengthen the alloy matrix. • The recrystallized Co 36 Fe 36 Cr 18 Ni 10 alloy achieved strength and ductility trade-off compared to 316L ss. • Twin boundaries can effectively inhibit pitting and corrosion crack formation and expansion. • The free state of elemental Co reacts with other elements can form a more stable substance in the passivation film. The high strength, ductility, and corrosion resistance of alloys are highly desirable functional materials for biomedical applications. Multi-component alloys with a single face-centered-cubic (fcc) phase structure can provide superior ductility, while microstructures such as twins and stacking faults (SF) can be incorporated into the matrix to improve the strength of the alloy without damaging plasticity. Here, we have developed a single-fcc phase alloy Co 36 Fe 36 Cr 18 Ni 10 with low stacking faults energy, which can effectively produce annealed twins by recrystallization annealing after cold rolling. The microstructure and mechanical properties of Co 36 Fe 36 Cr 18 Ni 10 compared to commercial 316L alloy was methodically investigated by EBSD, TEM, and tensile testing. The results reveal that the Co 36 Fe 36 Cr 18 Ni 10 alloy contains more twin boundaries and a high density of nano-twins and SFs in the microstructure, which effectively improve the strength of Co 36 Fe 36 Cr 18 Ni 10 alloy meanwhile maintaining a similar ductility to commercial 316L. The corrosion behavior of Co 36 Fe 36 Cr 18 Ni 10 and 316L in simulated body fluids has been investigated using electrochemical characterization, indicated that compared to 316L ss, pitting in Co 36 Fe 36 Cr 18 Ni 10 alloys is easily inhibited and rapid re-passivation, meanwhile the twin boundaries were effective in weakening the formation of corrosion pits and impeded the expansion of corrosion crack. Compare the surfaces of the two alloys after passivation, apart from the Cr 2 O 3 /Cr(OH) 3 contained in the passive film, the interactions between Co and other components in the passivation film produce more indissoluble substances with a lower enthalpy of formation that will enhance the passive film stability of Co 36 Fe 36 Cr 18 Ni 10 alloy. [ABSTRACT FROM AUTHOR]

• Grain size / surface chemical composition are keys for ITO films with high performance. • Oxygen vacancy and surface oxygen desorption depend on the annealing atmosphere. • Low conductivity of ITO film can be improved by annealing in reducing gas. • The resistivity and transmittance of ITO coated glass are 1.75 × 10−4 Ω cm and 88%. In this paper, tin doped indium oxide (ITO) films with high transparency and conductivity were fabricated on quartz by sol-gel method. The effect of four kinds of annealing atmospheres on the microstructure, morphology, surface chemical composition and optical-electrical properties has been investigated. Results show that the microstructure and morphology of the ITO films does not change much after heat treatment under different atmospheres. All annealed samples have the cubic bixbyite crystal structure of In 2 O 3 , with fine and uniformly distributed grains. The average grain size of each sample is approximately 10 nm. However, a noticeable dependence on the type of atmosphere is observed for oxygen vacancies and surface oxygen desorption. Different from oxidizing atmosphere, reducing or inert atmosphere is conducive to the formation of oxygen vacancies and desorption of adsorbed oxygen. Oxygen vacancies can effectively increase the carrier concentration of ITO. Oxygen desorption cannot only increase the carrier concentration, but also improve the carrier mobility. The issue for low conductivity of ITO nanocrystalline films can be solved by annealing in reducing atmosphere. This method can effectively control the grain growth and the chemical state of surface oxygen. The resistivity, average transmittance and Haacke FOM of the optimized ITO coated glass are 1.75 × 10−4 Ω cm, 88% and 0.0398 Ω−1, respectively. [ABSTRACT FROM AUTHOR]

Abstract: New types of CrAlN/ZrO2 nanomultilayers with different ZrO2 layer thickness were synthesized by reactive magnetron sputtering. The structure, mechanical properties and thermal stability were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM) and nano-indentation techniques. The results indicated that, when ZrO2 layer thickness was less than 1.0nm, tetragonal-structured ZrO2 layers were forced to transform to pseudomorphic fcc structure under the template effect of CrAlN layers and grew epitaxially with CrAlN layers, resulting in abnormal enhancement of mechanical properties. The maximum hardness and elastic modulus could respectively reach 47.2GPa and 538.9GPa when ZrO2 layer thickness was 1.0nm. With further increase of ZrO2 layer thickness, ZrO2 layers could not keep fcc structure and broke epitaxial growth structure, leading to the decrease of mechanical properties. High-temperature annealing revealed that hardness and elastic modulus decreased slightly when heated at a temperature below 900°C for 30min, while dropped significantly as annealing temperature raised to 1000°C. However, even after annealing at 1000°C for 30min, the nanomultilayers still retained hardness and elastic modulus as high as 36.8GPa and 465.7GPa, showing the excellent mechanical properties at elevated temperatures. [Copyright &y& Elsevier]

Abstract: A nanocrystalline surface layer is synthesized in Ni by surface mechanical attrition treatment (SMAT). The characterization of microstructure and composition indicates that foreign elements from hardened balls can permeate and diffuse into the surface layer during SMAT, which can further diffuse and homogenize in the surface layer when annealing at high temperature, leading to formation of new alloy. Foreign elements permeating into the surface layer during SMAT followed by diffusing and homogenizing at high temperature provide an alternative effective technology for surface modification. [Copyright &y& Elsevier]

Abstract: The interfacial evolution and shear strength of Sn3.8Ag0.7Cu–xNi composite solders on organic solderability preservative (OSP) finished pad were investigated at a temperature of 150°C aging for 0–1000h. It was found that all aged joints exhibited a duplex intermetallic compounds (IMCs) structure; i.e. a layer of (CuNi)6Sn5 close to the solder and a layer of Cu3Sn adjacent to the Cu substrate. The growth of the Cu3Sn layer was suppressed significantly after Ni particles addition, and the scallop-shape IMC with the composition of (CuNi)6Sn5 could be examined at the interface of all solder joints. In comparison with the non-composite joint, the IMC grain was refined significantly at the interface of composite joints. In addition, the mean thickness of interfacial IMC layers increased linearly with the square root of the aging time for all the diffusion couples. The Cu3Sn layer shows the fastest growth rate at the interface of non-composite. The fracture after the ball shear test occurred in the bulk solder for all as-reflowed joints and the aged SAC and SAC–0.5Ni joints. The fracture mode of SAC–1Ni and 2Ni joints transferred from an initial ductile type to a mixed type near the interface with the partial brittle fracture after 50h aging. [Copyright &y& Elsevier]

Abstract: The effects of multiple reflows (1, 2, 4, 6, 8, 10 numbers of reflow) on interfacial reaction and shear strength of Sn3.8Ag0.7Cu (SAC) and Sn37Pb (SP) joints were systematically investigated using electrolytic Ni/Au and organic solderability preservative (OSP) finished pad. In the case of OSP finished substrate, the well-known intermetallic compound (IMC) Cu6Sn5 was observed for both solders. While for the Ni/Au finished substrate, the IMC Ni3Sn4 and (CuNi)6Sn5 were formed on the interface of SP and SAC joints, respectively. With the increasing number of reflows, the thickness of IMCs on all reaction couples increased gradually and the IMC grain coarsened. The IMC growth kinetics showed that the interfacial IMC Cu6Sn5 was controlled by grain boundary diffusion and that the IMCs (Ni3Sn4 and (CuNi)6Sn5) near Ni layer had interactive diffusion control of grain boundary and volume diffusion. Moreover, IMC growth at Cu interface was faster than that at Ni interface, irrespective of the solder type. Shear test results showed that the shear force did not change much until eight numbers of reflow for each reaction couple. The ductile fracture indicated that the shear strength of solder joints could not be significantly influenced by the thickness and morphology of the interfacial IMC. [Copyright &y& Elsevier]

Abstract: The present work prepared composite lead free solders by adding 0.5, 1 and 2wt.% of dendrite Ni micro-particles to Sn3.8Ag0.7Cu solder paste. Melting behaviors of composite solders were determined by differential scanning calorimeter (DSC). The wetting ability was evaluated with the spread area on Ni/Au finished Cu pad. The interface microstructure, morphology and shear strength were examined for composite solder joints on the electrolytic Ni/Au metallized Cu substrate with one, two, four, and six reflows, respectively. It was found that the intermetallic compound (IMC) shifted from the needle-like (CuNi)6Sn5 on the non-composite joint to dual layers of facet-like (CuNi)6Sn5 and boomerang shape (NiCu)3Sn4 with 0.5wt.% Ni addition, and only boomerang shape (NiCu)3Sn4 was formed at the interface between the composite solder and Ni layer when Ni addition exceeded 1wt.%. The thickness of IMC increased with the increasing number of reflows. Regardless of the number of reflows, the shear strength of composite solder joints showed increased trend as Ni content increased. The fracture of all joints happened in the solder bulk, which revealed that the failure was ductile. [Copyright &y& Elsevier]

Red and brown inorganic pigments Mg 1-x Mn x Fe 2 O 4 (x = 0.0, 0.2, 0.3, 0.4, 0.5) with high far-infrared emissivity and high near-infrared reflectivity were synthesized by the xerogel-microwave method. The pure spinel structure of compounds was confirmed by various methods (X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), and Raman spectroscopy). From the XRD analysis, we can find that a shift in the decreased XRD angle is observed with the addition of the Mn2+ ions because of the radius differences between host ions (Mg2+) and dopant ions (Mn2+) as well as the John-Teller distortion. Furthermore, the results of XRD and Raman spectroscopy demonstrated that Mn dopants can inhibit the grain growth. Meanwhile, the reflective properties were measured by UV–vis–NIR spectrophotometer and the NIR solar reflectance values in the 1400–2500 nm range are over 66% with a maximum 82.9% (x = 0.2). In the experiment where Mn2+ replaced Mg2+ in MgFe 2 O 4 , the band gap decreased from 2.14 eV to 1.86 eV, which results in the decrease of the NIR solar reflectance in 800–1400 nm range. At last, the infrared emissivity of the samples was measured at room temperature, and the average emissivity is over 0.8 with maximum 0.85 (x = 0.5), which is due to the lattice distortion and the intensification of asymmetrical vibration of the Mn–O, Mg–O and Fe–O bonds. • Red and brown inorganic pigments Mg 1-x Mn x Fe 2 O 4 were synthesized by the xerogel-microwave method. • The pigments Mg 1-x Mn x Fe 2 O 4 possess the high far-infrared emissivity and high near-infrared reflectivity. • The pigments Mg 1-x Mn x Fe 2 O 4 could be candidates for "cool pigments". [ABSTRACT FROM AUTHOR]

In this work, graphene nanoplates/copper (GNPs/Cu) composites with a multi-layer structure were prepared through electrostatic self-assembly and electroless copper plating, enabling the uniform dispersion of GNPs in Cu matrix and thus improve the interfacial wettability of GNPs in Cu matrix. GNPs were arranged parallelly in the prepared Cu matrix composites, and GNPs in the same horizontal surface interweaved to form GNPs protective layers, which inhibited the splash and evaporation of molten Cu in the arc erosion tests. The arc erosion resistance of the composites enhanced with the increase of GNPs content. Meanwhile, the wettability and interface bonding strength of GNPs and Cu matrix has been improved, and GNPs were not easily separated from Cu matrix in the wear tests under electric current. The GNPs protective layers improved the wear resistance of the composites under electric current and inhibited the formation of erosion pits. • GO were adsorbed on the surface of flake Cu powders by electrostatic self-assembly. • Cu nanoparticles coated on the surface of GO by electroless Cu plating. • The surface-coated Cu nanoparticles improved the interfacial wettability of GNPs. • GNPs protective layers improved the arc erosion resistance of composites. • The electric wear resistance of GNPs/Cu composites were improved. [ABSTRACT FROM AUTHOR]

Magnetic ground state in the two-dimensional (2D) limit is fundamental issue and essential building block for next-generation nano-spintronic devices. Here, we report the observation of antiferromagnetic ordering in 2D MnPSe 3 by Raman spectroscopy. Thickness and temperature-dependent Raman spectroscopy confirms the antiferromagnetic ordering in MnPSe 3 down to atomically thin layers with trivial thickness-dependent Néel temperature from multiple evidence: the enhanced phonon Raman intensities, significant deviations from the anharmonic contribution of phonon frequencies due to spin-phonon coupling, and the occurrence of one-magnon Raman peak below the Néel temperature. The Raman vibration mode evolution studies reveal that the magnetic ion d-electron transfer is mediated by the nonmagnetic clusters of [P 2 Se 6 ]4-. Our work motivates the explorations of intriguing spin dynamics in 2D antiferromagnet and promotes the development of novel spintronic devices. • Magnetic ordering in layered MnPSe 3 was investigated by Raman spectroscopy. • Multiple Raman evidence supports existence of antiferromagnetic ordering in 2D MnPSe 3. • Néel temperature of MnPSe 3 is almost independent on thickness. [ABSTRACT FROM AUTHOR]

The development of economical, efficient, and durable bifunctional catalyst for overall water splitting is an attractive and challenging task. Herein, a novel defect-rich 2D/2D heterostructure is constructed by vertically growing S-doped NiMoO 4 (NiMoO 4 -S) nanosheets on nickel sulfide (Ni 3 S 2) nanosheet arrays supported on nickel foam (NF) using a two-step hydrothermal method. Benefiting from the hierarchical sheet-on-sheet heterogeneous nanostructure and abundant oxygen vacancies for more active sites, efficient electronic/mass transfer, and fast gas release, the synthesized NiMoO 4 -S/Ni 3 S 2 /NF electrode exhibits excellent electrocatalytic performance for HER (η 10 mA cm −2 = 107 mV) and OER (η 50 mA cm −2 = 285 mV). The alkaline water electrolyzer with NiMoO 4 -S/Ni 3 S 2 /NF as the positive and negative electrodes can provide a current density of 10 mA cm−2 with the potential of 1.52 V, which is below that of the commercial Pt||RuO 2 /NF system or many other reported systems. More importantly, the alkaline water electrolyzer offers a current density of 100 mA cm−2 at 1.85 V with outstanding durability of over 50 h. This research points to a promising route in designing transition metal-based bifunctional electrocatalysts for large-scale energy conversion applications. [Display omitted] • A novel defect-rich S-doped NiMoO 4 -S/Ni 3 S 2 2D/2D heterostructures catalyst on nickel foam (NF) was synthesized. • The NiMoO 4 -S/Ni 3 S 2 /NF has a unique sheet-on-sheet structure and abundant oxygen vacancies. • The NiMoO 4 -S/Ni 3 S 2 /NF exhibit superior overall water splitting performance in alkaline media. [ABSTRACT FROM AUTHOR]

Abstract Porous In 2 O 3 nanoplates with polycrystalline structure (pp-In 2 O 3 NPs) and single-crystalline structure (ps-In 2 O 3 NPs) were synthesized through a facile solvothermal combined with a post calcination process. The gas sensing performance of the In 2 O 3 nanoplates with different crystallinity and porosity was investigated. Compared with the pp-In 2 O 3 nanoplates, the ps-In 2 O 3 nanoplates exhibited significantly enhanced gas sensitivity and selectivity towards triethylamine (TEA). The enhancement of the gas response of the ps-In 2 O 3 NPs can be attributed to the larger pore size and single-crystalline structure. Larger pore size can facilitate the target gas to diffuse into the inner surface of the sensing materials and increase the contacting chances of target gas and surface adsorbed oxygen species, while single-crystalline structure can decrease a part of grain boundary junction barrier and enhance the conductivity of the sensing film. This work would be important for further understanding the gas sensing mechanism and developing high promising In 2 O 3 gas-sensing materials. Graphical abstract Image 1 Highlights • Porous single-crystalline and polycrystalline In 2 O 3 nanoplates were controllable prepared. • The morphology and structure of the products were analyzed thoroughly. • The ps-In 2 O 3 nanoplates exhibited enhanced gas sensing performance to triethylamine. • The porous and single-crystalline structure contributed to the sensing properties. [ABSTRACT FROM AUTHOR]

In this work, Ti matrix composite reinforced with 5 vol % TiC ceramic was prepared using in situ technologies, then various microstructures of the composite were obtained after it was treated with thermo-mechanical treatments applied in different temperature ranges with different deformation amplitudes. Widmanstatten, bimodal or fined α laths microstructure was obtained after it was treated by thermo-mechanical treatment performed in β phase field, in α+β phase field or in upper α phase field, respectively. The measured β transfuse temperature of the composite rises about 100 K compared to that of the monolithic matrix alloy, which resulted from the carbon solid solution of the matrix. The results of tensile tests showed that the composite strength was increased after the thermo-mechanical treatment, and the increase may be attributed to the effects of the load transfer from matrix to TiC particles and the refinement of the matrix microstructure. The TEM observation shows that the size of α colonies takes an important role to the equivalent grain size of the matrix, but the size of the thickness of α plates has minor effect on it. [ABSTRACT FROM AUTHOR]

Titanium (Ti) and its alloys have great application potential. However, their relatively poor surface hardness, wear resistance, corrosion resistance, and biological activity greatly limit their effectiveness in practical applications. As a surface treatment method, the micro-arc oxidation (MAO) process has attracted much attention because it does not require expensive production equipment and is simple to operate. This paper discussed and summarized the mechanism of micro-arc oxidation and some classic models, which require development to provide better understanding and guidance for future research. Subsequently, the influencing factors of the formation of the micro-arc oxidation coating during micro-arc oxidation process were analyzed in detail. In addition, common applications of micro-arc oxidation coatings, including biomedical applications, wear resistance, corrosion resistance properties, and decoration, were summarized independently. Finally, existing problems and future prospects of the titanium alloy micro-arc oxidation process were discussed to facilitate the wide application of titanium alloy MAO process. [ABSTRACT FROM AUTHOR]

The AlN/Y nanocomposite and nanomultilayered films with different Y contents were fabricated by the magnetron sputtering technique. The microstructures and mechanical properties of the AlN/Y nanocomposite and nanomultilayered films were characterized and measured, respectively. The AlN/Y nanocomposite film is composed of equiaxed AlN nanocrystallites encapsulated by the Y interfaces. When the Y:Al ratio is 2:23, Y interfaces can exist as the crystallized state and keep the epitaxial growth with the adjacent AlN nanocrystallites. Accordingly, the crystallization degree and mechanical properties are improved. The AlN/Y nanomultilayered film consists of the evident multilayered structure with distinct interfaces. When the Y-layer thickness is no more than 0.7 nm, Y layers are inclined to grow epitaxially with the adjacent AlN layers, leading to the improvement of crystallization degrees and mechanical properties. The interfacial evolutions and mechanical properties variations between AlN/Y nanocomposite and nanomultilayered films have the common feature as the Y content grows. It has been experimentally and theoretically verified that the AlN/Y nanocomposite and nanomultilayered films have the same coherent-interface strengthening mechanism. [ABSTRACT FROM AUTHOR]

TiB reinforced titanium matrix composite with a near alpha alloy matrix was fabricated using in situ technologies. The Widmanstatten microstructure evolution of the composite and the TiB whiskers realignment effect during thermo-mechanical processing were investigated, and the mechanical properties of the composite were measured. It was found that the microstructure of the composite is refined significantly by the thermo-mechanical processing due to the recrystallization of beta grains. With the increase in deformation amplitude, the value of probability density of small orientation angles of TiB whiskers along extension direction increases sharply. Strength of the composite was increased significantly by the thermo-mechanical processing, which results from the increase in the strengthening effect of TiB whisker and the microstructure refinement. The value of the thickness of alpha plates (b) without precipitated sillicide has minor effect on the strength of the composite but it becomes a non-ignorable strengthening factor after sillicide precipitation due to its dislocation hindering effect. [ABSTRACT FROM AUTHOR]

The NiCr/Al nanomultilayered films with different Al thicknesses (t Al) were prepared by magnetron sputtering. The structural evolution of the Al nanolayer with the increase in t Al was investigated. When the Al layer thickness changed from 1.2 nm to 2.4 nm, the Al layer could keep the co-epitaxial growth with the adjacent NiCr layer. Accordingly, the crystallization degree improved. When the Al layer thickness changed from 2.4 nm to 3.0 nm, the transformation from the coherent to incoherent interfaces took place between the NiCr and Al layers. Meanwhile, the co-epitaxial growth with the adjacent NiCr nanocrystallites was destroyed, the crystallinity and the grain size decreased, leading to the increase of the resistivity under the combined effects of the grain boundary scattering and interface scattering. The interfacial evolution of NiCr/Al nanomultilayered films was closely related to the changes of electrical properties. When the Al layer thickness changed from 3.0 nm to 3.6 nm, the surface quality of the film was improved, which effectively reduced the scattering of defects and vacancies during the electron transport, resulting in the decrease of the resistivity of the NiCr/Al nanomultilayered film. [Display omitted] • Al films inserted NiCr nanolayers with different thickness were synthesized. • The microstructure structure of NiCr was damaged with insertion of Al nanolayers. • The resistivity was renewedly increased with the change of interface structure. • The resistivity later deteriorates with the improvement of the surface quality. [ABSTRACT FROM AUTHOR]

ZrN and TiNiN nanolayers are alternately deposited on silicon substrate by magnetron sputtering. A series of ZrN/TiNiN nano-multilayer films with different Ni contents are prepared by varying the Ni:Ti volume ratio of the targets. The effects of Ni content on the microstructures and mechanical properties of ZrN/TiNiN nano-multilayer films are studied by X-ray diffractometer (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and nanoindentation instrument. The results show that with the increase of Ni content, the crystallization degree of ZrN phase first increases and then decreases. Besides, the hardness, elastic modulus and toughness of the films also increase first and then decrease with Ni content increasing. When Ni:Ti= 1:24, the ZrN/TiNiN nano-multilayer films obtain the highest hardness, elastic modulus and fracture toughness, which are 23.2 GPa, 317.8 GPa and 2.29 MPa·m1/2, respectively. This is mainly attributed to the best columnar crystal growth of the ZrN/TiNiN nano-multilayer film. The TiNiN layer changes into face centered cubic structure under the template of ZrN layer, and grows in coherent epitaxy with ZrN layer. ● A series of ZrN/TiNiN nano-multilayer films with different Ni contents are prepared by magnetron sputtering. ● When Ni:Ti= 1:24, the ZrN/TiNiN nano-multilayer films simultaneously obtain the highest hardness and fracture toughness. ● The high hardness and toughness are due to that the TiNiN layer grows in coherent epitaxy under the ZrN layer template. [ABSTRACT FROM AUTHOR]

The (AlCrTiZrHf)N high-entropy alloy nitride films were synthesized by reactive magnetron sputtering. The effects of different N 2 flow rates on the microstructures and mechanical properties of (AlCrTiZrHf)N films were studied by the X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), nanoindentation, coating friction and wear tester. The results show that the AlCrTiZrHf high-entropy alloy film presents an amorphous state. With the increase of the N 2 flow rate, the (AlCrTiZrHf)N high-entropy alloy nitride films transform to a face-centered-cubic (FCC) structure. When the N 2 :Ar ratio is 5:4, the hardness and elastic modulus of the films reach 33.1 GPa and 347.3 GPa, respectively. The strengthening effect is mainly attributed to the formation of saturated metal-nitride phases and the solid-solution strengthening of various elements. Meanwhile, the (AlCrTiZrHf)N film exhibits the low friction coefficient and superior wear resistance. Based on the excellent properties of high-entropy alloy nitride films, the (AlCrTiZrHf)N film presents a potential application in protective coating. Image 1 • The (AlCrTiZrHf)N high-entropy alloy nitride films with different nitrogen content were produced. • The (AlCrTiZrHf)N films transform to a face-centered-cubic (FCC) structure with the increase of the N 2 flow rate. • When the N 2 :Ar ratio is 5:4, the hardness and elastic modulus of the film reach the maximum of 33.1 GPa and 347. • GPa.4.The friction coefficient was 0.5. [ABSTRACT FROM AUTHOR]

Here we report on tunable bandgap engineering of single phase (Ni/Co) codoped ZnO nanoparticles controlled by different dopant concentrations. The as-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–visible near infrared spectroscopy (UV-VIS-NIR), photoluminescence (PL) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). In absorption spectra, a clear blue shift of 15 nm for the Ni/Co codoped ZnO nanoparticles was observed compared to pure ZnO nanoparticles. Moreover, it demonstrates that the value of energy bandgap changes from 3.55 eV to 3.71 eV by varying the dopant concentrations. Compared to pure ZnO nanoparticles, green emission PL peak intensity is significantly reduced in the doped ZnO nanoparticles, attributed to the significant decrease in intrinsic defects. Our results improve the understanding of optical and structural properties of Ni and Co codoped ZnO nanoparticles as these nanocrystalline structures could be potential candidates for optoelectronic devices. [ABSTRACT FROM AUTHOR]

CoMn-layered double hydroxide (LDH) nanowires are successfully embedded on the surface of nickel foam (NF) through a simple one-step hydrothermal method. The morphology and electrochemical properties of the samples can be controlled using different molar ratios of Co and Mn salts. CoMn LDH nanowires on NF with Co 2+ /Mn 2+ molar ratio of 3:1 exhibit excellent electrochemical properties, high specific capacitance (1409 F g −1 at current density of 1 A g −1 ), good cycling stability (93.2% retention after 3000 charge-discharge cycles), and excellent performance rate (71.1% retention at 10 A g −1 ) when used as an electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

A new type of electroactive composite material based on tungsten trioxide (WO 3 ) and poly (tri(4-(2′-thienyl)) phenylamine) (P3TPA) was prepared. Using the WO 3 /P3TPA as electroactive material, the electrochromic device was fabricated, and the electrochromic properties of WO 3 /P3TPA were investigated. Compared with WO 3 , the coloring switching time and the bleaching switching time of WO 3 /P3TPA was decreased. The response speed became faster. The open-circuit memory of WO 3 /P3TPA became better. The coloration efficiency of WO 3 /P3TPA increased. [ABSTRACT FROM AUTHOR]

Copper-chromium-zirconium (CuCrZr) is tailored using additive manufacturing, particularly laser powder bed fusion (LPBF). Due to high thermal conductivities and high reflectivity of infrared laser irradiation, it is still challenging to fabricate copper alloys using the LPBF technique. To address the issue, a short wavelength laser (515 nm) was employed in the LPBF process. In this work, the CuCrZr alloys were built with optimized building parameters such as powder of 485 W, scanning speed of 400 mm/s, and hatching distance of 0.09 mm. The relative density of the samples was found to be 98.07 %. The as-built samples exhibit good mechanical properties with ultimate tensile strength (UTS) of 447 ± 13 MPa, yield strength (YS) of 400 ± 11 MPa, total failure elongation (EL) of 10 ± 3 %, and Vickers hardness of 130 ± 15 HV). However, the electrical property is poor with 30 ± 1 %IACS. The high tensile stress and low electrical conductivity may attribute to the dislocation cells. Moreover, the dissolved Cr atoms result in poor conductivity. By direct aging treatment at 500 °C for 1 h, excellent mechanical properties (UTS = 566 ± 18 MPa, YS = 487 ± 13 MPa, EL = 15 ± 1 %, Vickers hardness = 161 ± 15 HV) were achieved while maintaining a good conductivity (64 ± 3 % IACS). The main contribution to the increase in YS is attributed to (I) the nanoscale Cr precipitated homogeneously in the copper matrix during the direct aging treatment and (II) the remaining high dislocation density near the dislocation cells. The enhancement of the electrical conductivity is attributed to the decomposition of the supersaturated solid solution. • CuCrZr alloys were fabricated by laser powder bed fusion with green laser (wavelength= 515 nm), and the effect volume energy density increased greatly. • The UTS of the as-fabricated CuCrZr under the optimized parameters (485 W for power, 400 mm/s for scanning speed and 0.09 mm for hatching distance) can reach the highest value (approximately 460 MPa) where the alloy has a relative density of 98.07 %. • By applying a direct aging hardening, CuCrZr alloy exhibited a high strength (585 MPa). • Body centered cubic Cr and Cu x Zr y precipitations strengthened alloys by applying a direct aging hardening. [ABSTRACT FROM AUTHOR]

Up-conversion is a promising technique for harvesting sub-band-gap photons in photovoltaic devices. The implementation and characterization of rare-earth doped up-converters on a-Si:H solar cells are investigated. Three up-conversion phosphors, β-NaYF 4 :Yb 3+ 20%/Er 3+ 1%, β-NaYF 4 :Yb 3+ 25%/Ho 3+ 1% and β-NaYF 4 :Yb 3+ 60%/Tm 3+ 0.5%, are developed and employed as low energy convert materials for a-Si:H solar cells. Two different ways of adhering the up-converter to the a-Si:H solar cell have been implemented: by dissolving the powder in the polydimethylsiloxane (PDMS) and by compressing it into solid slice with a tablet pressing machine. The performance of a-Si:H solar cells integrating the up-converters is investigated under both 980 nm infrared laser diode and simulated solar light source (AM1.5G) illumination. The Current-Voltage measurements reveal that the β-NaYF 4 :Yb 3+ 20%/Er 3+ 1% up-conversion phosphor performs both up-conversion and scattering functions in improving the overall performance of a-Si:H solar cell. [ABSTRACT FROM AUTHOR]

• We successfully designed and synthesized a new type of non-equiatomic Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA, which has excellent corrosion resistance in the human body fluids, and also has the mechanical properties required for coronary stent materials. • Hank's simulated body fluid was used to simulate human environment, and there are currently few studies on the corrosion resistance of high-entropy alloy in the human environment. • Our designed Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA has less Ni content than common HEA, and we added Ti into our high-entropy alloy, which can make it have better biocompatibility, corrosion resistance and mechanical properties. A new type of non-equiatomic Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA was designed and synthesized, and its corrosion resistance was compared with 304 SS in Hank's simulated body fluids to verify its feasibility as an alternative for existing coronary stent materials. Electrochemical tests showed that the corrosion current density of Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA was 10−6 in order of magnitude, which was about 1/6 of that of 304 SS, and the impedance value of Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA was 105 in order of magnitude, which was about 7 times that of 304 SS. Scanning electron microscopy testing showed that after 120 h of continuous salt spray corrosion, the surface of 304 SS showed obvious corrosion morphology compared with Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA, and it was corroded with clear grain boundaries. After 6 h of potentiostatic polarization, a passive film was formed on the surfaces of Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA and 304 SS respectively, and the composition of the passive film of the two materials was analyzed by X-ray electron spectroscopy. Compared with 304 SS, the passive film formed on Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA is rich in Co and Cr elements, and the high Content of Cr and Ni makes Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA have higher corrosion resistance in Hank simulated body fluid. The high content of Fe2+ oxide in the passive film is the main reason why 304 SS is less resistant to corrosion than Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA in Hank's simulated body fluid. [ABSTRACT FROM AUTHOR]

• TiBw/nano-silicide addition improved the oxidation resistance of Ti alloy at 1123 K. • Nano-silicide led to the formation of a network structure oxide film. • The enhancers weak O adsorption and binding energy calculated by DFT calculations. [Display omitted] The challenge of enhancing the high-temperature oxidation resistance of titanium alloys is hereby addressed by the addition of TiB whiskers and nano-silicide. The cyclic oxidation tests results showed that the weight gains of the composites with reinforcements were less than that of titanium alloy, and the oxidation film of the silicide/composite only appears little peeling after heating at 1123 K for 100 h. The grains were refined by the introduction of reinforcements, thus the high-density grain boundary can be also used as the nucleation site of oxidation products to refine the oxide grains and effectively inhibit the internal diffusion process of oxygen. Additionally, nano-silicide distribution at grain boundaries cause short-circuit diffusion, resulting in preferential oxidation at grain boundaries thus forming a network structure, which effectively hinders the inward diffusion of oxygen and better inhibits the growth of oxidation scale. DFT calculation shows that TiBw and nano silicide reinforcement with weak oxygen binding ability can reduce the adsorbed oxygen atoms and prevent the further oxidation growth of the matrix. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ce3+/Mn2+ doped glass-ceramics containing β-Zn2SiO4 nano-crystals were prepared. [•] The glass-ceramics showed a tunable-color emission. [•] The resonant energy transfer from Ce3+ to Mn2+ via a dipole–quadrupole mechanism. [Copyright &y& Elsevier]

The microstructure and properties of Cu-0.42Cr (wt.%) and Cu-0.45Cr-0.14Ti (wt.%) alloy subjected to cold rolling and aging treatment are investigated through tensile testing, electrical conductivity measurement, scanning electron microscopy, and transmission electron microscopy. Results show that the tensile strength of Cu-0.45Cr-0.14Ti (wt.%) alloy enhances as the degree of deformation increases, but the degree of deformation slightly influences electrical conductivity. When deformation is changed, electrical conductivity is basically unchanged. The good combination of strength and electrical conductivity, which reach 610 MPa and 55.4% IACS, respectively, can be obtained in the Cu-0.45Cr-0.14Ti (wt.%) alloy after 80% cold rolling and aging at 450 °C for 15 min. Ti inhibits the growth of the Cr precipitation phase and enhances the precipitation strengthening effect. Ti mainly exists in the matrix in the form of solute atoms, which do not form a separate lattice structure after aging treatment. • The alloy material is prepared by a process method combining solid solution aging treatment and deformation treatment. • Ti element enhances the effect of age hardening and significantly improves the mechanical properties of the alloy. • Titanium atoms segregate around the Cr phase to slow down the rate of precipitation coarsening. • Ti atoms have never formed a separate lattice structure in the Cu-0.45Cr-0.14Ti (wt.%) alloy. [ABSTRACT FROM AUTHOR]

Transition metal phosphides (TMPs) have been regarded as promising substitutes for lithium/sodium storage mainly due to the high capacity and good security. However, great challenges have to face in ultimate application, especially the problem of active substances uneven mixing in the electrode preparation process and structural collapse during circulation. Herein, we report a novel and facile strategy for synthesis 3D flexible conductive network hybrids of PA-derived Co 2 P nanoparticles encapsulated into N-doped carbon skeleton (Co 2 P/NC). The as-prepared Co 2 P/NC nanofibers acting as freestanding binder-free anode material can provide highly dispersed Co 2 P nanoparticles in cross-linked frameworks and effectively alleviate the structural collapse, bring about superior rate performance during repeated cycles. When applied in lithium-ion battery, the Co 2 P/NC nanofibers exhibit high capacity (1041.5 mA h g−1 after 200 cycles at 100 mA g−1), excellent rate performance and long lifespan (retain a steady reversible capacity of 563.6 mA h g−1 with CE ∼100% after 1000 cycles at 10 A g−1). As for sodium-ion batteries, it also exhibits long-term stability and better reversible capacity (retains 132.3 mA h g−1 after 2500 cycles at 1.0 A g−1). The SEM results show that the morphology of Co 2 P/NC after 1000th lithium (10 A g−1)/sodium (1.0 A g−1) storage circulation can still maintain good integrity. Image 1 • Highly dispersed Co 2 P nanoparticles wrapping by N-doped carbon conductive support effectively restrain volume expansion. • Co 2 P/NC nanofibers can be directly acted as freestanding binder-free electrode with superior flexibility and conductivity. • The as-prepared Co 2 P/NC exhibit excellent high-rate performance and superior cycling stability in LIBs and SIBs. • For LIBs, a steady reversible capacity of 563.6 mA h g-1 can be obtained after 1000 cycles at 10 A g-1. • For SIBs, a steady reversible capacity of 132.3 mA h g-1 can be obtained after 2500 cycles at 1.0 A g-1. [ABSTRACT FROM AUTHOR]

Hot compression tests of the Cu-Co-Si-Ti and Cu-Co-Si-Ti-Ce alloys were carried out on the Gleeble-1500 simulator at 0.001–10 s−1 strain rates and 500–900 °C deformation temperatures. Compared with the Cu-Co-Si-Ti alloy, the flow stress of the Cu-Co-Si-Ti-Ce alloy increased under the same deformation conditions. The micro texture of the Cu-Co-Si-Ti and Cu-Co-Si-Ti-Ce alloys were analyzed by EBSD. In addition, the texture of Cu-Co-Si-Ti alloy deformed at 700 and 800 °C is {011} <100> Goss texture and {112} <111> copper texture, respectively. However, the {001} <100> cubic texture and {011} <100> Goss texture in Cu-Co-Si-Ti-Ce alloy deformed at 700 and 800 °C were obtained, respectively. The constitutive equations of Cu-Co-Si-Ti and Cu-Co-Si-Ti-Ce alloys were obtained. The activation energy of Cu-Co-Si-Ti and Cu-Co-Si-Ti-Ce alloys is 500.79 kJ/mol and 539.94 kJ/mol, respectively. The Co 2 Si precipitate was found in both the Cu-Co-Si-Ti and Cu-Co-Si-Ti-Ce alloys, while the Co 2 Si precipitate of Cu-Co-Si-Ti-Ce alloy is smaller than that of the Cu-Co-Si-Ti alloy. Moreover, the dislocation density of Cu-Co-Si-Ti-Ce alloy is higher than Cu-Co-Si-Ti alloy under the same conditions. Finally, Ce addition increased flow stress and activation energy, and inhibited the dynamic recrystallization, which can be attributed to the higher dislocation density and finer Co 2 Si precipitate. The CDRX and DDRX mechanisms are the two main DRX mechanisms for Cu-Co-Si-Ti and Cu-Co-Si-Ti-Ce alloys during hot deformation. Image 1 • Hot deformation behavior of the Cu-Co-Si-Ti alloy was investigated. • The texture evolution was obtained from the pole figures and inverse pole figures. • Deformation activation energy is Q = 539.94 kJ/mol by the regression analysis. [ABSTRACT FROM AUTHOR]