Theoretical analysis of the inverse Edelstein effect at the LaAlO3 / SrTiO3 interface with an effective tight-binding model: Important role of the second dxy subband

The two-dimensional electron gas formed at interfaces between SrTiO3 and other materials has attracted much attention since extremely efficient spin-to-charge current conversion has been recently observed at these interfaces. This has been attributed to their complicated quantized multi-orbital structures with a topological feature. However, there are few reports quantitatively comparing the conversion efficiency values between experiments and theoretical calculations at these interfaces. In this study, we theoretically explain the experimental temperature dependence of the spin-to-charge current conversion efficiency using an 8×8 effective tight-binding model considering the second dxy subband, revealing the vital role of the quantization of the multi-band structure.

Impact of ZrO2 Additive on Microstructure, Magnetic Properties, and Temperature Dependence of the Initial Permeability of LiTiZn Ferrite Ceramics

The effect of the diamagnetic ZrO2 addition on the microstructure and magnetic properties of LiTiZn ferrite ceramics, including the shape and parameters of the temperature dependence of the initial permeability, has been investigated. The defect structure of ferrite ceramic samples is assessed according to our earlier proposed method based on mathematical treatment of the experimental temperature dependencies of the initial permeability. The method is recommended for defects monitoring of soft ferrite ceramics and ferrite products. It was found that the defect structure of ferrite ceramics increased by 350% with an increase in the concentration of the ZrO2 additive in the range of (0–0.5) wt.%. In this case, for the same samples, the increase in the true physical broadening of reflections is only 20%, and the coercive force by 50%. Simultaneously, the maximum of the experimental temperature dependence of the initial permeability dropped by 45%. The microstructure of all samples is characterized with a similar average grain size according to the SEM data. However, samples with the 0.5wt.% of ZrO2 are characterized by the formation of conglomerates. A linear relationship was obtained between the defect structure and the width of the reflections, which indicates that this parameter is related to the elastic stress of ferrite ceramics.

Temperature Dependence of Raman Frequency Shift in SrWO4 Crystal Studied by Lattice Dynamical Calculations

The frequency shift of the Raman modes in strontium tungstate (SrWO4) was investigated in the temperature range from 15 to 295 K. The experimental temperature dependence of the shift was analyzed using both the lattice dynamical calculations and the lattice perturbative approach. We found that the quartic anharmonic term of the first-order perturbation and the cubic term of the second-order perturbation, as well as the thermal expansion, contribute to the temperature shift of the highest-frequency Ag(ν1) mode. The values of the temperature sensitivity of the frequency shift of the Raman modes at room temperature were measured, which is important for developing high-power crystalline Raman lasers and frequency shifters.

VAPOUR-LIQUID EQUILIBRIUM IN SYSTEMS WITH ISOBUTYL ACETATE, ACETIC ACID AND METHYL ETHYL KETONE

The experimental temperature dependence of the vapour pressures of isobutyl acetate, acetic acid and methyl ethyl ketone were determined, and isobaric vapour-liquid equilibrium data of binary systems of methyl ethyl ketone + isobutyl acetate and methyl ethyl ketone + acetic acid were obtained. The experimental data were processed using the Antoine and Riedel equations and the NRTL and Wilson local composition equations, respectively. Comparison of the experimental and calculated data confirmed the adequacy of the vapour-liquid equilibrium mathematical simulation.

Magnetic and Transport Properties of Ferromagnetic-PEEK Polymer Nanocomposite Prepared via Ion-Implantation

ABSTRACTThin films of magnetic-nanocomposite are prepared using a novel two step ion-implantation technique. Structural assessment via TEM of the ion bombarded iron-polymer composite shows development of fine magnetic nanoparticles (20–50 A) in a carbonaceous matrix. The experimental temperature dependence of conductivity of the composite, in the temperature range 10–300 K, follows the exponential law σ = σo exp [(-To/T)γ], where To and γ are constants. The observed higher values of γ > 1 imply the presence of more than one conducting channel in the composite. The secondary conducting channels, beside hopping conductivity, may arise from the conducting graphitic matrix around Fe nanoparticles. The room temperature magneto-transport measurement indicates a 0.5% change in magnetoresistance at 0.5T field. The observed anomalous Hall voltage confirms the presence of magnetic nature of nanoparticles.