A. N. Babushkin

Electric properties of Cu-Ag-Ge-As-Se ionic conductors at high pressures

The effect of static pressure on the electric properties of vitreous materials Cu1 − xAgxGeAsSe3, where x = 0.95, 0.9, and 0.85 is studied. The pressure dependences of impedance and dielectric loss tangent at pressures 15–45 GPa are analyzed. The ranges of substantial changes in the electrical properties of the samples are found.

Effect of pressures on the electrical properties of multicomponent copper and silver chalcogenides

The effect of high pressures (up to 45 GPa) and frequencies of the alternating-current (ac) electric field (10 Hz–10 MHz) on the electrical properties of multicomponent copper and silver chalcogenides has been studied. The behavior of the direct-current (dc) electrical resistivity of the samples has been analyzed under uniaxial pressure along the measuring electric field.

Pressure and temperature dependences in p-ZnAs2 at high pressures

Kinetic effects in p-ZnAs2 were measured at hydrostatic (P ≤ 9 GPa) and quasi-hydrostatic (to P ≤ 50 GPa) pressures on pressure buildup and depressurization. A conclusion on the occurrence of two phase transitions was made: I–II at P = 9–15 GPa and II-III at P = 30–35 GPa. Based on the temperature dependences of electrical resistance, it was shown that the conductivity is determined by activation mechanisms in a temperature range of 250–400 K; in this case, the activation energy changed with temperature and pressure. The pressure dependences of the activation energy and the coefficient R0, which characterizes the mobility, concentration, and effective mass of carriers, were calculated.

Synthesis and characterization of the new high pressure phases ACu3 V4O12(A=Gd, Tb, Er)

New ACu3V4O12 (A=Gd, Tb, Er) phases have been prepared at high pressure and high-temperature conditions (P∼8–9 GPa, T∼1000°C) in a toroid-type high pressure cell. These compounds crystallize in the cubic symmetry with a perovskite-like structure. At ambient pressure, they are paramagnetic and have activation-type conductivity. The effect of high pressure (10–50 GPa) on the electrical properties of the materials was analyzed in the temperature range from 78 to 300 K. Pressure ranges of the transition from activation type to metallic conductivity have been determined. The crystal structure of ACu3V4O12 (A=Gd, Tb, Er) was found to be stable up to 50 GPa.

Effect of high pressures on the electrical properties of the perovskite-like phases of ACu3V4O12

The electrical properties of new perovskite-like compounds ACu3V4O12 (A = Gd, Er, Tm) were studied at high pressures (10–50 GPa). The effect of the composition and structure of the compounds on the baric ranges of substantial changes in the behavior of the electrical characteristics was analyzed.

Influence of high pressure on the electrical properties of amorphous chalcogenides of the Ag-Ge-As-S system

New AgGe1 + xAs1 − xS3 (x = 0.1, 0.4–0.9) silver chalcogenides are synthesized and certified. Their electrical properties are studied at pressures of up to 45 GPa by means of impedance spectroscopy. Regions of significant variations in electrical properties are detected via analysis of an impedance hodograph, the baric dependencies of resistance, and the dielectric loss tangent.

Thermoelectric Properties of a Ferromagnetic Semiconductor Based on a Dirac Semimetal (Cd 3 As 2 ) under High Pressure

The pressure dependences of thermal emf (a parameter that ranks among the most sensitive to phase transformations) are studied for the purpose of identifying baric phase transitions in the 10–50 GPa interval in the Cd3As2 + MnAs (44.7% MnAs) structure formed by ferromagnetic MnAs granules in a semiconductor Cd3As2 matrix.

Magnetic and electrical properties of crystalline materials based on indium and copper chalcogenides in a wide range of temperatures and pressures

The effect of temperatures (2–300 K) and high pressures (to 50 GPa) on the electrical and magnetic properties of crystalline materials based on copper and indium chalcogenides with the general formula (InB)1‒x(CuAB2)x, where A = As, Sb; and B = S, Se, and also crystalline CuInSe2 and CuInS2, has been studied.

Studies of electrical resistivity of highly oriented pyrolytic graphite under high pressures at room temperature

The pressure dependence of electrical resistivity of highly oriented pyrolytic graphite is investigated at room temperature. The time needed to stabilize a sample’s resistance at constant pressure ranges from one hour to several days. The influence of the thickness of a sample and a current passed through it on the magnitude and pronouncedness of characteristic features in the pressure dependence of graphite resistance is found.

Influence of external effects on the electrical properties of high pressure perovskite-like phases CaCu3Ti4-xVxO12

Samples of high pressure perovskite-like phases CaCu3Ti4-xVxO12, x = 0.1, 0.2, 0.3, 0.4 and 0.5 were synthesized at high-pressure and high-temperature conditions in a toroid-type high-pressure chamber. Their electrical properties were studied by impedance spectroscopy in the frequency range from 1 Hz to 30 MHz at temperatures of 300 to 600 K and at pressures of 10 to 30 GPa.