Search

The results of experimental studies of the resistivity, Hall effect, and magnetoresistance of Cd3As2 + kMnAs composites (k = 20, 30, 44.7 mol %) in a toroid-type high-pressure chamber, which makes it possible to create a hydrostatic pressure up to 9 GPa at room temperature in magnetic fields up to 5 kOe, are presented. With increasing pressure, the electrical resistance of samples with different manganese contents is shown to increase at different rates. In the pressure range 4.2–4.4 GPa, a reversible structural transition is observed. An increase in pressure suppresses the positive component of the magnetoresistance; at pressures of P ≈ 1.0 and P ≈ 2.6 GPa, a region of negative magnetoresistance is observed. With a further increase in pressure, the magnetoresistance increases nonmonotonically up to Р ≈ 4.3 GPa, i.e., the phase transition region. [ABSTRACT FROM AUTHOR]

The results of studying the thermal emf of composites Cd3As2 + n mol % MnAs (n = 10, 20, 30, 44.7) at high pressures up to 50 GPa are presented. In the pressure ranges of P = 28–35 GPa (n = 10, 20), 20–35 GPa (n = 30), and 30–35 GPa (n = 44.7), all the materials studied exhibit specific features in the behavior of the thermal emf S(P) (extrema, inflection points on the curves or hysteresis). At a pressure exceeding 40 GPa, the thermal emf changes weakly or barely changes with an increase and a subsequent decrease in pressure. [ABSTRACT FROM AUTHOR]

In this article, we report research data for the isothermal magnetization of a composite consisting of Cd3As2 Dirac semimetal and MnAs ferromagnet (30 mol %) at pressures up to 5 GPa. A magnetic transformation in MnAs inclusions, the size of which presumably varies from a micro- to nanoscale, has been found to be similar to that in bulk MnAs compound, except for a hysteresis in the range of magnetostructural transformation. Under hydrostatic pressure, a magnetization maximum has been revealed at pressures P ≥ 0.77 GPa, which is indicative of ferromagnetic ordering improvement. The conclusion has been drawn that that the above features are due to the superparamagnetic nature of nanometer-sized MnAs inclusions in the Cd3As2 matrix. [ABSTRACT FROM AUTHOR]