Mechanism for Improved Curie Temperature and Magnetic Entropy Change in Sm-Doped FeZrB Amorphous Alloys.

In the present work, FeZrSmB (x = 2, 4) amorphous alloys (AAs) were successfully synthesized into the shape of 40-micrometer-thick ribbons and their magnetic properties were measured. The FeZrSmB (x = 2, 4) AAs exhibited a rather high maximum magnetic entropy change (-Δ): ~3.53 J/(K × kg) near 317 K for x = 2 and ~3.

The exchange between anions and cations induced by coupled plasma and thermal annealing treatment for room-temperature ferromagnetism.

Two-dimensional (2D) materials, with outstanding magnetic properties at room temperature, are highly desirable for the future spintronic and nanoscale electronic industry. However, most of the 2D systems are not of magnetic nature due to thermal fluctuations. Herein, we propose a novel strategy to induce robust room-temperature ferromagnetism in the originally nonmagnetic 2D ReS by the exchange between anions and cations.

A High Precision and Multifunctional Electro-Optical Conversion Efficiency Measurement System for Metamaterial-Based Thermal Emitters.

In this study, a multifunctional high-vacuum system was established to measure the electro-optical conversion efficiency of metamaterial-based thermal emitters with built-in heaters. The system is composed of an environmental control module, an electro-optical conversion measurement module, and a system control module. The system can provide air, argon, high vacuum, and other conventional testing environments, combined with humidity control.

Hexanuclear Co Dy , Zn Dy , and Co Y Complexes with Defect Tetracubane Cores: Syntheses, Structures, and Magnetic Properties.

A hexanuclear heterometallic cluster of composition [Dy Co (L) (NO ) (OH) (C H OH) ] ⋅ 2 C H OH (1) was synthesized by employing a Schiff base 2-(((2-hydroxy-3-methoxybenzyl) imino)methyl)-4-methoxyphenol (H L) as ligand and utilizing Dy(NO )  ⋅ 6H O and Co(NO )  ⋅ 6H O as metal ion sources. X-ray single-crystal diffraction analysis indicated that complex 1 contains a defect tetracubane core and possesses central symmetric structure, with two Dy ions being in the central body position of the molecule and four Co ions being arranged at the outer sites. Magnetic studies reveal that complex 1 behaves as single-molecule magnet (SMM) with energy barrier of 27.

Evolution from a single relaxation process to two-step relaxation processes of Dy single-molecule magnets via the modulations of the terminal solvent ligands.

To explore the influences of magnetic interactions on the relaxation dynamics of single-molecule magnets (SMMs) and to understand the relationship between single-ion relaxation and the relaxation of a molecular entity, it is very important to design dinuclear lanthanide-based SMMs with two-step relaxation processes. Here, three Dy complexes of compositions [Dy(L)(NO)(MeOH)] (1), [Dy(L)(NO)(EtOH)] (2), and [Dy(L)(NO)(DMF)]·0.5EtOH (3) (HL = 2-(((2-hydroxy-3-methoxybenzyl)imino)methyl)-4-methoxyphenol) were successfully synthesized via elaborately introducing different terminal solvent ligands.

Designing asymmetric Dy single-molecule magnets with two-step relaxation processes by the modification of the coordination environments of Dy(iii) ions.

The reaction of Dy(NO3)3·6H2O and an asymmetric Schiff-base linker 5-chloro-2-(((2-hydroxy-3-methoxybenzyl)imino)methyl) phenol (H2L) afforded a dinuclear compound [Dy2L2(HL)(NO3)(EtOH)]·0.5C2H5OH (1). Complex 1 features two inequivalent Dy(iii) sites, where three ligand sets (one HL- moiety and two L2- groups) are shared by two Dy(iii) ions.

Investigation of catalyst-assisted growth of nonpolar GaN nanowires via a modified HVPE process.

The growth of nonpolar GaN nanowires along the [101[combining macron]0] orientation has been demonstrated via a modified hydride vapor phase epitaxy (HVPE) process using GaCl3 and NH3 as precursors. The morphology and structure evolution as a dependence of the growth parameters was thoroughly studied to elucidate the nucleation and crystallization of nonpolar GaN nanowires. It has been found that the V/III ratio and temperature are critically important for the formation of high-quality nonpolar GaN nanowires.

Simultaneous detection of trace Ag(I) and Cu(II) ions using homoepitaxially grown GaN micropillar electrode.

Driven by the motivation to quantitively control and monitor trace metal ions in water, the development of environmental-friendly electrodes with superior detection sensitivity is extremely important. In this work, we report the design of a stable, ultrasensitive and biocompatible electrode for the detection of trace Ag and Cu ions by growing n-type GaN micropillars on conductive p-type GaN substrate. The electrochemical measurement based on cyclic voltammetry indicates that the GaN micropillars exhibit quasi-reversible and mass-controlled reaction in redox probe solution.

CuP-NiP Hybrid Hexagonal Nanosheet Arrays for Efficient Hydrogen Evolution Reaction in Alkaline Solution.

The development of efficient and low-cost hydrogen evolution reaction electrocatalysts has been regarded as a promising approach to produce sustainable and clean fuels to solve the energy crisis and environmental problems. Herein, 3D hybrid CuP-NiP hexagonal nanosheet arrays are successfully prepared on nickel foam (CuP-NiP/NF). Benefiting from synergistic effects and strong chemical coupling existing at the interface, the CuP-NiP/NF electrode exhibits a low overpotential of 103 mV at a current density of 10 mA cm, which is 47 and 100 mV less than that for NiP/NF and CuP/NF, respectively.

Stoner-enhanced paramagnetism in tungsten tetraboride.

We demonstrate that tungsten tetraboride (WB4), a heavy transition metallic compound without magnetic atoms, is an exchange-enhanced paramagnet revealed by the magnetization and specific heat measurements. WB4 has a small effective magnetic moment of 0.53 μB/fu.

Field-induced spin-flop in antiferromagnetic semiconductors with commensurate and incommensurate magnetic structures: Li2FeGeS4 (LIGS) and Li2FeSnS4 (LITS).

Li2FeGeS4 (LIGS) and Li2FeSnS4 (LITS), which are among the first magnetic semiconductors with the wurtz-kesterite structure, exhibit antiferromagnetism with TN ≈ 6 and 4 K, respectively. Both compounds undergo a conventional metamagnetic transition that is accompanied by a hysteresis; a reversible spin-flop transition is dominant. On the basis of constant-wavelength neutron powder diffraction data, we propose that LIGS and LITS exhibit collinear magnetic structures that are commensurate and incommensurate with propagation vectors km = [1/2, 1/2, 1/2] and [0, 0, 0.

Structural and relative stabilities, electronic properties and possible reactive routing of osmium and ruthenium borides from first-principles calculations.

First-principles calculations are employed to provide a fundamental understanding of the structural features and relative stability, mechanical and electronic properties and possible reactive route for osmium and ruthenium borides. The structural searches and calculations of the formation enthalpy identify a low-energy monoclinic phase for OsB3 with P2(1)/m symmetry, an orthorhombic phase for OsB4 with Pmmn symmetry, an orthorhombic phase for RuB3 with Pnma symmetry and a hexagonal phase for RuB4 with P63/mmc symmetry. Also, the structure transition at high pressure is also predicted for MB3 and MB4 (M = Os and Ru).

Electronically induced ferromagnetic transitions in Sm5Ge4-type magnetoresponsive phases.

The correlation between magnetic and structural transitions in Gd(5)Si(x)Ge(4-x) hampers the studies of valence electron concentration (VEC) effects on magnetism. Such studies require decoupling of the VEC-driven changes in the magnetic behavior and crystal structure. The designed compounds, Gd(5)GaSb(3) and Gd(5)GaBi(3), adopt the same Sm(5)Ge(4)-type structure as Gd(5)Ge(4) while the VEC increases from 31  e(-)/formula in Gd(5)Ge(4) to 33  e(-)/formula in Gd(5)GaPn(3) (Pn: pnictide atoms).

Synthesis, crystal structure, and electronic properties of the tetragonal (RE(I)RE(II))3SbO3 phases (RE(I) = La, Ce; RE(II) = Dy, Ho).

In our efforts to tune the charge transport properties of the recently discovered RE(3)SbO(3) phases (RE is a rare earth), we have prepared mixed (RE(I)RE(II))(3)SbO(3) phases (RE(I) = La, Ce; RE(II) = Dy, Ho) via high-temperature reactions at 1550 °C or greater. In contrast to monoclinic RE(3)SbO(3), the new phases adopt the P4(2)/mnm symmetry but have a structural framework similar to that of RE(3)SbO(3). The formation of the tetragonal (RE(I)RE(II))(3)SbO(3) phases is driven by the ordering of the large and small RE atoms on different atomic sites.

Does the real ReN2 have the MoS2 structure?

Rhenium nitride (ReN(2)) with the hexagonal MoS(2) structure was recently synthesized by metathesis reaction under high pressure. Here the calculated elastic and thermodynamic stabilities and chemical bonding show that the MoS(2) phase is unstable based on first-principles calculations. Meanwhile, the MoS(2)-type ReN(2) compound may be stabilized by nitrogen-vacancies from X-ray diffraction and supercell calculations.

Electron-deficient Eu(6.5)Gd(0.5)Ge6 intermetallic: a layered intergrowth phase of the Gd5Si4- and FeB-type structures.

A novel electron-poor Eu(6.5)Gd(0.5)Ge₆ compound adopts the Ca₇Sn₆-type structure (space group Pnma, Z = 4, a = 7.

Suppression of antiferromagnetic interactions through Cu vacancies in Mn-substituted CuInSe2 chalcopyrites.

Stoichiometric and Cu-poor Cu(0.95-x)Mn(0.05)InSe(2) (x = 0-0.

Decoupling the electrical conductivity and Seebeck coefficient in the RE2SbO2 compounds through local structural perturbations.

Compromise between the electrical conductivity and Seebeck coefficient limits the efficiency of chemical doping in the thermoelectric research. An alternative strategy, involving the control of a local crystal structure, is demonstrated to improve the thermoelectric performance in the RE(2)SbO(2) system. The RE(2)SbO(2) phases, adopting a disordered anti-ThCr(2)Si(2)-type structure (I4/mmm), were prepared for RE = La, Nd, Sm, Gd, Ho, and Er.

Crystal structure, coloring problem and magnetism of Gd(5-x)Zr(x)Si4.

Ternary Gd(5-x)Zr(x)Si(4) silicides were synthesized by arc melting of the constituent elements and subsequent heat treatments. The Gd(5-x)Zr(x)Si(4) phases adopt the orthorhombic Gd(5)Si(4)-type (space group Pnma) structure for x≤ 0.25 and the tetragonal Zr(5)Si(4)-type (space group P4(1)2(1)2) structure for x≥ 1.