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Abstract The FeVO 4 nanoparticles are synthesized by a new and facile electrostatic spray assisted coprecipitation method. The effects of calcination temperature and crystal structure on electrochemical properties are discussed. X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption isotherms and galvanostatic cell cycling are used to characterize the structure and electrochemical performance of the FeVO 4 nanoparticles. Compare to the crystalline FeVO 4 , the amorphous contemporary prepared by a low-temperature thermal treatment exhibits an outstanding electrochemical performance, which deliver a high initial coulombic efficiency of 80.4%, stable cycling performance with a reversible capacity of 115.6 mAh g−1 after 100 cycles and high rate capacity of 89.7 mAh g−1 at 800 mA g−1. Highlights • The amorphous and crystalline FeVO 4 are prepared by a new ESAC method. • The amorphous FeVO 4 can be as a cathode for sodium-ion batteries. • The amorphous FeVO 4 shows excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

MnO@multi-walled CNTs (MnO@MWCNTs) composite film electrodes with porous structure are synthesized by the improved electrostatic spray deposition (ESD) setup. The content of 5.47 wt% MWCNTs is found to be optimal, which can improve the conductivities of MnO film electrodes without destroying their porous structure and obtain good cycling performance (588 mAh g −1 after 100 cycles at 1 C) and high rate capabilities (424 mAh g −1 at 5 C). The effects of MWCNTs on the morphology of the electrodes and the electrochemical performances have been studied. It is found that the electrostatic repulsion between the charged spray droplets can be remarkably reduced by excessive adding MWCNTs, which leads to the breakdown of the 3D porous morphology of the MnO film electrodes and the electrochemical performance becomes worse. [ABSTRACT FROM AUTHOR]

The structural, elastic, mechanical anisotropy and thermodynamic properties of tetragonal copper-titanium intermetallic compounds (Cu Ti ICs) have been investigated by using a first-principles density functional theory (DFT). The calculated elastic constants index that tetragonal Cu Ti ICs are mechanically stable. The elastic properties, including shear modulus, Young’s modulus, ratio B/G and elastic anisotropy are derived from the elastic data C ij . According to the calculated ratio B/G value, the tetragonal Cu Ti ICs is one kind of ductile materials, and the brittleness of tetragonal Cu Ti ICs rank as follows: Γ-CuTi > Cu 4 Ti 3 > CuTi 2 > Cu 3 Ti 2 > CuTi. Moreover, mechanical anisotropy of Cu Ti ICs is analyzed by the directional dependence of Young’s modulus. Finally, Debye temperature, melting point and thermal conductivity are predicted through different empirical formula. There will be highlight implications of these calculated data for future Cu Ti ICs materials design and analysis. [ABSTRACT FROM AUTHOR]

The effect of seed solution amount variation on the aspect ratio and microstructure of gold nanorods (GNRs) using a seed-mediated method has been studied. The ultraviolet–visible (UV–Vis) absorption spectra for all samples shows that the wavelength of transverse surface plasmon resonance (TSPR) peak appeared at around 534 ± 10 nm regardless of the amount of seed solution used. The wavelength of longitudinal surface plasmon resonance (LSPR) of GNRs increased from 750 to 812 nm with seed solution amount being raised from 40 to 320 μl. Then, the wavelength of GNRs slightly decreased from 812 to 789 nm when the seed solution amount increased from 320 to 800 μl. The aspect ratio (AR) value measured from TEM images increased from 3.32 ± 0.07 to 4.03 ± 0.08 when the seed solution amount increased from 40 to 320 μl. Then, the AR value slightly decreased from 4.03 ± 0.08 to 3.95 ± 0.08 when the seed solution amount increased from 320 to 800 μl. The synthesized product of gold nanoparticles included spheres, nanorods and rhombus-shaped particles. The results of NBED and EDS revealed that the rhombus-shaped nanoparticles were bimetallic, containing gold and silver. [ABSTRACT FROM AUTHOR]

Controlling the aspect ratio (AR) of gold nanorods (GNRs) via covariation of the total concentrations of HAuCl 4 ([HAuCl 4 ]) and ascorbic acid ([AA]) has been studied. Characteristics of GNRs were examined by transmission electron microscopy (TEM) and ultraviolet–visible (UV–vis) absorption spectrophotometry. TEM results showed that single crystalline GNRs grew along an elongated growth direction of [100]. TEM results also revealed that the quantity of plate shaped and nearly spherical nanoparticles increased as the total amount of [HAuCl 4 ] and [AA] decreased. The AR value measured from TEM images decreased from 4.74 to 2.41 as the total amount of [HAuCl 4 ] and [AA] was increased from 0.305 to 2.44 mM. The UV–vis absorption spectra of all samples showed that the wavelength of transverse surface plasmon resonance (TSPR) peak appeared at around 530 nm for all samples. The wavelength of longitudinal surface plasmon resonance (LSPR) peak increased from 640 to 894 nm as the total amount of [HAuCl 4 ] and [AA] decreased from 2.44 to 0.305 mM. The wavelength of LSPR peak shows a red-shifted effect except when the total amount of [HAuCl 4 ] and [AA] was 0.122 mM. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ag nanowires show the polarization transmittance regardless of the concentration. [•] Effect of polarization transmittance increased with increasing the concentration. [•] Find the suitable conditions for bubble formation. [ABSTRACT FROM AUTHOR]

Ti substituted P2-phase Na 0.8 (Li 0.33 Mn 0.67-x Ti x)O 2 (x = 0, 0.05, 0.1 and 0.2) cathodes are synthesized by a simple sol-gel method. The effects of Ti substitution on the crystal structure, morphology and electrochemical performances of Na 0.8 (Li 0.33 Mn 0.67-x Ti x)O 2 are also analyzed. Combining the advantages of smaller particle size, enhanced structural stability and higher Na+ diffusion rate, the sample for x = 0.1 exhibits a high initial coulombic efficiency of 87.8%, good cyclic stability of 121 mA h g−1 after 100 cycles, and an outstanding rate performance of 85 mA h g−1 at 500 mA g−1. These results suggest that Ti substitution can be an effective method to enhance the electrochemical properties of P2-type Na 0.8 (Li 0.33 Mn 0.67-x Ti x)O 2 cathodes. • The properties of P2–Na 0.8 (Li 0.33 Mn 0.67)O 2 cathode are systematically studied. • Proper Ti doping in Na 0.8 (Li 0.33 Mn 0.67)O 2 enhances the electrochemical performances. • Na 0.8 (Li 0.33 Mn 0.57 Ti 0.1)O 2 is a competitive cathode for sodium-ion batteries. [ABSTRACT FROM AUTHOR]

The α variant selection of integral as-deposited Ti-6Al-4V prepared by laser solid forming (LSF) has been investigated by Electron Backscattered Diffraction (EBSD). Six types of α variants exist all areas in the deposited cuboid although its microstructure varies from basket-weave to Widmanstätten (and undeveloped basket-weave) to ultrafine basket-weave along building direction. Clusters of three α variants always dominate in medium steady zone until the columnar to equiaxed transition (CET transition) occurs. α variant selection causes strong alteration of high angle grain boundaries (HAGBs), which might be correlated with self-accommodation of shape strains. Super variant selection in medium steady zone. Image 1 • The α variant selection of LSF Ti-6Al-4V has been investigated by EBSD. • Six types of α variants exist all areas in varying macro- and microstructures. • Clusters of three variants with 60° α/α GB always dominate in columnar grains. • The variant selection might be related with self-accommodation of shape strains. [ABSTRACT FROM AUTHOR]

Abstract DyScO 3 single crystals were grown by the Czochralski method, and the magnetic properties and anisotropic magnetocaloric effect (MCE) have been investigated. It is found that DyScO 3 single crystal possesses an Ising-like antiferromagnetic magnetic structure below T N ∼3.5 K with the Ising easy axes lying in the ab plane. Meanwhile the strong magnetic anisotropy was observed in DyScO 3 single crystal. In the magnetic field changes of 0–20 kOe and 0–50 kOe, the maximum magnetic entropy changes of 17.04 J/kg K and 21.18 J/kg K were obtained along the b axis, with the corresponding refrigerant capacity (RC) values of 128.62 J/kg and 417.33 J/kg, respectively. With magnetic fields of only 10 kOe and 20 kOe imposed, it was noteworthy that the prominent rotating magnetic entropy changes of 8.49 J/kg K and 16.94 J/kg K at 9.5 K were observed by rotating the DyScO 3 single crystal within the bc plane, respectively. The prominent low-field rotating MCE indicates DyScO 3 single crystal can be used as an excellent potential candidate for low-field rotating magnetic refrigeration near the liquid helium temperature, which is a simpler way by rotating the refrigerants under a low constant magnetic field instead of the general method of changing the imposed magnetic field. Highlights • Magnetic anisotropy, MCE and RMCE were investigated in DyScO 3 single crystal. • − Δ S M max value is 17.04 J/kg K along the b axis under Δ H of 0–20 kOe. • The − Δ S M R values are 8.49 J/kg K and 16.94 J/kg K in the bc plane under 10 kOe and 20 kOe respectively. [ABSTRACT FROM AUTHOR]

We report successful growth of millimeter-sized high quality single crystals of V 3 S 4 , a candidate topological semimetal belonging to a low-symmetry space group and consisting of only low atomic number elements. Using density functional theory calculations and angle-resolved photoemission spectroscopy, we show that the nonmagnetic phase of monoclinic V 3 S 4 hosts type-II Dirac-like quasiparticles which opens a sizable gap due to spin orbit coupling, as well as theoretical multiple nodal lines that are eliminated also by spin orbit coupling. These results suggest that relativistic effects give rise to profound modifications of the topological properties even in compounds with low-weight elements. • We report successful growth of high quality millimeter-sized V3S4 single crystals by chemical vapor transport method. • We show that V3S4 possesses both type-II Dirac cones and topological nodal lines in its nonmagnetic phase without SOC. • When SOC is included, the Dirac point opens a 120 meV gap, and all topological nodal lines vanish. [ABSTRACT FROM AUTHOR]

Second phase particles (SPPs) that are formed during melting process have a significant effect on the hot extrusion and re-extrusion processes of NiTi. In the present work, the evolution of Ti 4 Ni 2 O x (with x ≤ 1) particles during hot extrusion and re-extrusion of near equiatomic Ti-50.6 at.% Ni billets, and their effects on the surrounding matrix microstructure were studied using OM, SEM, TEM and EBSD. The analyses indicate that Ti 4 Ni 2 O x (with x ≤ 1) are the particles that precipitate in the austenite matrix. After hot extrusion and re-extrusion, some particles are elongated and preferentially oriented along the ED. Eventually, these elongated particles are located at the grain boundaries. The size distribution of the SPPs is non-uniform after the first hot extrusion, and this non-uniformity increases after re-extrusion. The presence of non-deforming SPPs produces inhomogeneous deformation with a sharp increase in dislocation density in the surrounding matrix. This is shown to exert a profound effect on the processes of recovery and recrystallization for the surrounding matrix. [ABSTRACT FROM AUTHOR]

IN718Plus superalloy with hierarchical microstructure has been successfully manufactured by laser directed energy deposition (LDED). Along building direction, microstructure varies from composing of epitaxial columnar grains oriented along <001> γ direction to equiaxed grains in flower like configuration. Striped Laves phase and fine γ'/γ'' precipitates form in the columnar grains, and would transform into fine Laves phase particles and nanoscale γ' precipitates at equiaxed layer. To improve the compositional homogeneity and microstructural stability, high temperature solution treatment has been explored on the superalloy. The treatment would not affect the morphology and orientation of columnar grains, but would redissolve Laves phase precipitates. Double aging treatment has also been performed to obtain homogeneous distributed γ' precipitates, and the synergistic regulation of microstructure enhances the mechanical property significantly, as causing the room temperature yield strength and tensile strength increased from 0.88 GPa and 1.14 – 1.04 GPa and 1.28 GPa, respectively. Moreover, the excellent mechanical property would be maintained upon 704 ℃, with yield strength of 0.93 GPa, tensile strength of 1.04 GPa and high elongation of 27.3%. [Display omitted] • IN718Plus superalloy with hierarchical microstructure has been successfully manufactured by LDED. • As-deposited microstructure is composed of columnar to equiaxed grains with hierarchical Laves phase and γ'/γ'' precipitates. • Appropriate heat treatment process has been explored as 1100 ℃/1.5 h + 788 ℃/8 h + 704 ℃/8 h to ameliorate the performance. • Excellent 704 ℃ tensile properties have been obtained with tensile strength of 1.04 GPa and elongation of 27.3%. [ABSTRACT FROM AUTHOR]

The good thermoelectric properties of AgKTe at room temperature are identified by using the first-principles density functional theory. Based on the optimized geometrical structure, electronic properties, we calculate the relaxation time with deform potential theory. The transport coefficients including electronic thermal conductivity, Seebeck coefficient, and electrical conductivity are obtained with semiclassical Boltzmann transport theory and relaxation time approximation. The lattice thermal conductivity at room temperature is calculated by using the Debye-Callaway model. The thermoelectric figure of merit of AgKTe is determined and compared with other typical thermoelectric materials. The results demonstrate that for both the n -type and the p -type AgKTe, the maximum thermoelectric figure of merit of 1.7 can be achieved at room temperature by means of tuning the carrier concentration. Therefore, AgKTe could be a promising candidate of thermoelectric materials. [ABSTRACT FROM AUTHOR]

Thin film with highly-oriented Ag nanowires on glass surface was prepared by a dip-coating technique from a Polyvinylpyrrolidone/ethanol solution. Ag nanowires were firstly prepared by seed mediated method, and then dispersed in solution by mechanical and ultrasonic dispersion. The alignment of the Ag nanowires mainly depends on the concentration of the polyvinylpyrrolidone (PVP) and the pulling speed during dip-coating. It is observed that there is obvious optical polarizing performance in the 1400–1900 nm wavelength range. This approach is expected to offer a low-cost preparation method for large-scaled assembly of functional nanoscale electronic and photonic structures. [ABSTRACT FROM AUTHOR]

Controllable synthesis of semiconductor nanocrystals is an attractive issue yet still remains challenging. Here, we describe our efforts toward this direction by a simple colloidal method to engineer quinary Cu 3 ZnInSnSe 6 (CZITSe) nanocrystals with different crystal phases and shapes. In this work, wurtzite and zincblende CZITSe nanocrystals with different morphology could be selectively synthesized by tuning the addition order of the Se precursor to metal reactants solution. Furthermore, the optical and electrical behavior of the resultant nanocrystals exhibits obvious structure-dependent properties. This work will open new exciting avenues to explore the controllable synthesis of multicomponent semiconductor nanocrystals with metastable structures. [ABSTRACT FROM AUTHOR]

A series of LiMn 2 O 4 cathodes with different Mn3+ contents are synthesized by a hydrothermally assisting method combined with a high-temperature solid phase process based on manganese-based metal organic frameworks (MOFs). The effect of NaOH addition on the morphology, structure and electrochemical properties of the LiMn 2 O 4 cathode is investigated. The obtained samples all exhibit obvious octahedral morphology, corresponding to the cubic spinel structure with high crystallinity. Sample LMO-3 prepared with three times the molar amount of NaOH as PTA has the highest Mn3+ content, approximately 46.02%. The (100) and (110) crystal planes are exposed due to the higher Mn3+ content and the special truncated octahedral morphology, which endows LMO-3 with higher capacity and excellent rate performance. Specifically, the first specific capacity of LMO-3 is 140.6 mAh·g−1 at a rate of 1 C, and the capacity retention is 102.82% after 500 cycles. The corresponding capacity retention is 90.2% after 1000 cycles at 10 C. The spinel LiMn 2 O 4 cathode synthesized by taking manganese-based MOFs as a precursor has great potential in practical applications. • Manganese-based Metal Organic Frameworks synthesized in NaOH solution induces the truncated octahedron formation of LiMn 2 O 4. • The truncated octahedral morphology exposure the (110) and (100) crystal planes and improves the electrochemical performance. • The synthesis reaction spontaneously induces the formation of oxygen vacancies and increases the Mn3+ content. • The capacity of LiMn 2 O 4 is 103 mAh·g-1 at 10 C, and the capacity retention rate is 90.2% after 1000 cycles. [ABSTRACT FROM AUTHOR]

The present paper reports six distinctive doping effects of γ-Si 3 N 4 resulted with C, O and F dopants. Based on density functional calculations, 15 doped structures from different doping method are appreciated with formation and binding energies. Six of them, which are considered to be more easily to synthesize, are put into investigations of electronic and optical properties. The successively reduced energy gap, transformation of semiconductor to conductor and enhanced visible-light absorption coefficient are found. The mechanisms for six doping effects are explored with four concentrations and elucidated on the basis of the electronic structure. [ABSTRACT FROM AUTHOR]

• Anisotropic magnetic and MCE properties were investigated in TbScO 3 single crystal. • The − Δ S M max of 23.71 J/kg K was obtained along the easy a axis with Δ H of 0–50 kOe. • A rotating magnetic entropy change 23.63 J/kg K at 50 kOe is obtained in anisotropic TbScO 3 crystal. • The prominent MCE and RMCE propose TbScO 3 single crystal to be excellent candidate for low-temperature magnetic refrigeration. Magnetocaloric effect (MCE) shows great potential in refrigeration field and especially fundamental scientific research with cooling requirement. In this work, we studied the anisotropic magnetic and magnetocaloric properties of TbScO 3 single crystal, a popular substrate used for depositing epitaxial ferroelectric films. Our results indicate a strong antiferromagnetic ordering below T N ~ 3.1 K in orthorhombic TbScO 3 single crystal. Large magnetocrystalline anisotropy exists between the magnetic easy ab plane and the hard c axis, leading to a giant anisotropic MCE. In field changes of 20 and 50 kOe along the a axis, large magnetic entropy changes reach 15.25 and 23.71 J/kg K at 3 K and 7 K, respectively, while the magnetic entropy changes along the c axis are negligible. As a result, large rotating magnetic entropy changes of 15.27 and 23.63 J/kg K are obtained by rotating TbScO 3 single crystal with constant fields of 20 and 50 kOe lying in the ac plane. The large anisotropic MCE of TbScO 3 single crystal indicates this material as a promise refrigerant candidate for rotating magnetic refrigeration technique near the helium temperature. [ABSTRACT FROM AUTHOR]

Highlights: [•] Novel optical properties of CdS doped with Co are explored. [•] Co concentration of 7.26wt.% is the crucial point for optical properties of CdS. [•] The mechanism can be understood through the electronic properties. [Copyright &y& Elsevier]

In this study, highly active TiO 2 sensitized by a novel axial substituted subphthalocyanine H 12 SubPcB-OPHCH 2 COOH (SubPc-3) was successfully prepared via a solvothermal method. Based on the crystallographic strategy, a new packing motif of SubPc-3 consisting of ligand-convex concave-concave head-head π-interaction was discovered for the first time, which affected its catalytic performance significantly. Furthermore, the DFT and TD-DFT methods were used to study the electronic feature and excited-state properties in SubPc-3 utilizing an optimized structure. By examining the degradation of methyl orange (MO) and bromophenol blue (BB) under visible light, the photocatalytic activities of the nanocomposites were investigated. The photocatalytic degradation rate of MO and BB degradation with TiO 2 /SubPc-3 are 97.8% and 99.5%, which are approximately 5.26 and 1.41 times compared to pure TiO 2 , respectively. Besides, the reusability studies indicated that the photocatalytic activity of TiO 2 /SubPc-3 (25:1) could be maintained above 90.1% after five circulating photo-degradation. This work revealed the correlation between π-interaction of sensitizer and photocatalytic performance, as well as further confirmed the great potential of TiO 2 /SubPc-3 photocatalytic materials in environmental remediation. Image 1 • A novel packing motif of SubPc-3 consisting of ligand-convex concave-concave head-head π-interaction was prepared. • The photocatalytic performance of TiO 2 /SubPc-3 for MO and BB degradation has been improved obviously. • The photocatalytic activity of TiO 2 /SubPc-3 (25:1) could be maintained above 90.1% after five circulating photodegradation. • The TD-DFT calculations showed that the S1 excited states of SubPc-3 are controlled by HOMO to LUMO electronic transition. [ABSTRACT FROM AUTHOR]

Developing high-efficient and Earth-abundant electrocatalysts toward hydrogen evolution reaction (HER) is strongly desired for electrochemical water splitting but remains a considerable challenge. Herein, we propose a 3D hierarchical Fe(PO 3) 2 @Cu 3 P heterostructure nanotube arrays on Cu foams for promising HER catalysts. The HER performance can be tuned by changing FeCl 3 concentrations and the optimized cathode exhibits excellent HER activity in 1 M KOH with a low overpotentials of 108 mV @ 10 mA cm−2 and a small Tafel slope of 84 mV dec−1. Furthermore, this electrode delivers high electrochemical durability with stable operation for 24 h. Such high performance can be ascribed to the unique hierarchical heterostructure with large electrochemical surface area, synergistic effect and fast electron transport. Our study can provide new inspiration for rational construction of copper-based hierarchical nanomaterials for HER electrodes and other energy-related applications. Hierarchical Fe(PO 3) 2 @Cu 3 P nanotube hybrids on 3D copper foam were synthesized, which demonstrate excellent activity toward hydrogen evolution in alkaline solution with robust stability. Image 1 • Hierarchical Fe(PO 3) 2 @Cu 3 P nanotube arrays were successfully synthesized on Cu foam. • The hybrid catalysts exhibit excellent activities for HER in alkaline media. • Synergistic effect between Fe(PO 3) 2 and Cu 3 P was found by XPS. • The hybrid catalyst exhibits considerable stability for HER. [ABSTRACT FROM AUTHOR]

A technique was proposed to concentrate the distribution of set voltages. After a plasma treatment, the stability of the high-resistive state (HRS) increased, and the distribution of set voltages was more concentrated at 0.8 V, with a sufficient HRS/LRS resistive ratio (∼100x). In addition, the surface of the TiN electrode became rougher, causing oxygen to enter the TiN electrode and form a TiON layer, which acts as an oxygen reservoir. The reservoir is confirmed and the conduction model is supported by both electrical and material analyses. We propose that the observed improvement is due to the difference in the TiN electrode surface. Image 1 • Applied the plasma treatment on electrode to stabilize set voltage. • Construct the physical model to explain abnormal current conduction. • Complete electrical and material analysis were performed in this work. [ABSTRACT FROM AUTHOR]