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The β phase of tungsten has attracted great interest for spintronic applications due to its higher spin Hall angle compared to other elemental solids and large spin–orbit torque, but the stability of this phase is yet to be well understood as many different results are there in the literature mainly based on the film thickness, temperature, and overall growth conditions. The growth of films by sputter deposition has emerged as a promising technique to achieve β-W owing to its compatibility with current spintronic technology. We demonstrate here the efficient ability of dc magnetron sputtering to grow stable β-W films up to a thickness of ∼180 nm at room temperature by varying a set of deposition parameters like pressure, power, and deposition time and discuss the various underlying mechanisms. From these results, the optimized set of deposition parameters for growing β-W films is given. A clear understanding of the influence of oxygen in the atomic structure of β-W is obtained by varying the thickness of the films. This is confirmed from the ab initio molecular dynamics (MD) simulations, where the atomic structure is influenced by the oxygen doping concentration. A stable polycrystalline β phase can be achieved by controlled doping of oxygen. Additionally, a phase transformation from α to β with the doping of oxygen is also evident by MD simulations. [ABSTRACT FROM AUTHOR]

HoCrO3, a member of the rare-earth chromate family, is known to exhibit an orthorhombic structure with Pbnm space group in bulk at room temperature. We have employed the pressure driven powder consolidation technique, spark plasma sintering, for synthesizing HoCrO3 powder-compact, which exhibits a superior quality with fewer defects over that synthesized by conventional solid-state sintering (resulting in a large reduction of charge carrier mediated extrinsic dielectric contribution). The powder compact shows magneto-dielectric coupling but does not exhibit a detectable ferroelectric phase in the range of 50 K to 300 K. Low temperature Raman spectra show structural distortions below 250 cm−1, indicating Ho ion displacements. Temperature evolution of the crystal structure using synchrotron x-ray diffraction reveals a probable structural phase transition below 240 K. Pyrocurrent measurement, together with synchrotron x-ray diffraction analysis, further points to a magneto-structural transition at 100 K. [ABSTRACT FROM AUTHOR]

FeGa3 is a well known intermetallic semiconductor with a band gap, which is induced by d-p hybridization. In this work, we present the results of experimental and theoretical studies on the effect of Al substitution in FeGa3, obtained by X-ray diffraction (XRD) study, temperature dependent resistivity measurement, room temperature Mössbauer measurement, and density functional theory based electronic structure calculations. It is observed that up to x=0.178 in Fe(AlxGa1-x)3, which is the maximum range studied in this work, Al substitution reduces the lattice parameters a and c, preserving the parent tetragonal P42/mnm crystal structure of FeGa3. Rietveld refinement of the XRD data shows that Al atoms replace Ga atoms located at the 8j sites in FeGa3. A comparison of the trends of the lattice parameters and energy band gap obtained from the calculations and experimental measurements also confirms that Al atoms primarily replace the Ga atoms in the 8j site. The band gap of Fe(AlxGa1-x)3 for x=0.178 is reduced by ≈24% as compared to FeGa3. The system thus has a lot of promise for applications in band gap engineering in infra-red devices. [ABSTRACT FROM AUTHOR]