Quantum Size Effects and Transport Phenomena in PbSe Quantum Wells and PbSe/EuS Superlattices

It is established that the room-temperature dependences of transport properties on the total thickness of PbSe layers d in PbSe/EuS superlattices exhibit an oscillatory behavior. It is shown that the oscillation period Δd practically coincides with the period of the thickness oscillations observed earlier in single PbSe/EuS quantum well. The non-monotonic character of these dependences is attributed to quantum size effects. The theoretically estimated and experimentally determined Δd values are in good agreement

Size effects in chlorine doped PbSe thin films

The possibility of obtaining strongly degenerate (≈ 3·10²⁰ сm⁻³) PbSe thin films (d = 5 – 220 nm) with n-type conductivity by thermal evaporation in vacuum of PbSe crystals doped with PbCl₂, with subsequent condensation onto (001) KCl substrates was established. It was shown that the films had high homogeneity degree, no grain structure was observed. The thickness dependences of thermoelectric properties (the Seebeck coefficient S, the Hall coefficient RH and the electric conductivity σ) of thin films were obtained. In the thickness range d ≈ 5 ÷ 30 nm, oscillation properties were observed with growth of d that are attributable to electron gas quantization. The calculation of S(d) dependence on the assumption of size quantization with regard to contribution of several subbands and the thickness dependence of the Fermi energy was shown to be in agreement with the experimental data. In the region of d > 30 nm there was growth of S and σ with thickness, which is attributable to manifestation of classical size effect and interpreted in the framework of Fuchs-Sondheimer and Mayer theories

Dependences of thermoelectric properties on the thickness of thin films of indium doped lead telluride

Dependences of thermoelectric properties (the Seebeck coefficient S, the electric conductivity σ, the Hall coefficient RH, the carrier mobilityμ and the thermoelectric power P = S²·σ) on the thickness d (d = 10 – 255 nm) of thin films prepared by vacuum evaporation of indiumdoped PbTe crystals and subsequent condensation on (111) BaF₂ substrates were obtained. With decreasing thickness of films to d ≈ 40 nm, there is n- to p-type inversion of conduction which is related to a change in thermodynamic equilibrium conditions and partial reevaporation of lead and/or indium atoms. Extremes were found on the thickness dependences of properties at d₁ ≈ 20 nm which is indicative of hole gas quantization. In the range of thicknesses with n-type conduction there is a smooth change in thermoelectric properties with thickness which testifies to manifestation of classical size effect and is sufficiently well described in the framework of the Fuchs-Sondheimer theory

Structure and properties study of V-based membrane alloys for ultra-high purity hydrogen production

The reported study was funded by RFBR according to the research project No.16-38-00759 мол_а, the equipment of Shared Research Center Ural-M was used to make this study

HIGH-ENTROPY ALLOYS CoCrFeNi: STRUCTURE AND THERMAL PROPERTIES

A comprehensive experimental study of the thermophysical properties and structure of high-entropy CoCrFeNi alloys in the initial state obtained by electric arc melting and in the crystalline state after long-term high-temperature annealing has been carried out.Работа выполнена при финансовой поддержки Российского научного фонда (№ 23-22-00137)

MICROSTRUCTURE AND PROPERTIES OF V-Ti-Ni MEMBARANE ALLOYS

Alloys based on vanadium having bcc structure are considered as an alternative to palladium membrane alloys for hydrogen filtering. The advantages of vanadium alloys are relatively high hydrogen permeability and low prime cost. Both bulk and surface characteristics of the membrane alloys influence on filtering efficiency. The alloys of V-Ti-Ni system were investigated by means of XRD, SEM, XPS and hydrogen permeability techniques.Работа выполнена в рамках Государственного задания ИМЕТ УрО РАН по теме № 0396-2015-0079. Работа выполнена с использованием оборудования ЦКП “Урал-М”

SPECTRAL ANALYSIS IN EVALUATION OF ELECTROCHEMICAL BEHAVIOR OF HIGH-ENTERTROPIC ALLOYS GdTbDyHoSc AND GdTbDyHoY

In this paper, time series of potential fluctuations in samples of high-entropic alloys GdTbDyHoSc and GdTbDHoY at different current densities were obtained. Spectral methods of time series analysis were used to establish the character of corrosion behavior of the alloys under study.Работа выполнена при финансовой̆ поддержке Российского научного фонда, в рамках проекта № 21-43-00015

STRUCTURE AND PROPERTIES OF V90Cо10 MEMBRANE ALLOY

Vanadium-based alloys having bcc structure are promising materials for hydrogen separation due to their relatively high hydrogen permeability and low cost in comparison with palladium alloys. Bulk and surface characteristics of the V90Co10 membrane alloy was examined by XRD, SEM, and X-ray photoelectron spectroscopy, confocal scanning microscopy, respectively.Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 16-38-00759мол_а. Работа выполнена с использованием оборудования ЦКП “Урал-М” и НОЦ НАНОТЕХ УрФУ

ANTIFRICTION COVERING OFCu-Fe-Al-Pb FOR SLIDING BEARINGS

The samples of connecting rod bushes of world’s manufacturers were analyzed. The new composition of antifriction coating on a copper basis is presented.Исследование выполнено за счет гранта Российского Научного Фонда (проект РНФ №15-13-00029)