It is well known that one way to reveal electron scattering with a spin-flip is to study fine structures of quantum oscillations of longitudinal magnetoresistance [1].The quantum oscillation extremes of longitudinal magnetoresistance result from the fact that the probability of charge-carrier scattering is dramatically increased with the magnetic field where the Fermi energy is equal to the Landau level (or sublevel). This, in turn, leads to an increase in resistance.It is well-known [1] that the longitudinal magnetoresistance in a quantizing magnetic field is written asThe field dependence of the relaxation time has the following form:where m * and n are the charge-carrier effective mass and concentration, e is the electron charge, τ(ξ) is the relaxation time, τ(ξ H ) is the relaxation time in a magnetic field, ξ is the Fermi energy, ξ H is the Fermi energy in a magnetic field, ħ is the Planck constant divided by 2π, Ω is the cyclotron frequency, Ν = 0, 1, 2,… is the principal quantum number, g is a factor of the spectroscopic energy-level splitting, µ В is the Bohr magneton, and Н is the magnetic-field strength. It is seen from the foregoing formulas that the resistance maximum occurs in resonance conditions. The zero maxima in quantum oscillations of the transverse and longitudinal magnetoresistance occuring due to zero Landau-level splitting under conditions of a strong magnetic field (Ωτ >> 1), quantization of the charge-carrier motion (ħΩ > kT), and spin Landau-level splitting (gµ В Н >> kТ) were first revealed in [2-6] (τ is the momentum relaxation time of a charge-carrier, k is the Boltzmann constant, and Т is the absolute temperature).According to [1], a zero maximum of the longitudinal magnetoresistance occurs only in the case where scattering flips the electron spin, since it is in this case where there is a probability of charge-carrier transition from the lower zero Landau sublevel to the upper zero one.This work is aimed at finding the temperature range where charge-carrier scattering with a spin flip takes place in a quantizing magnetic field.To this end, the quantum oscillations of longitudinal magnetoresistance ρ zz (Н) are measured on electron indium arsenide with the electron concentration n 77 = 1.5⋅10 17 cm -3 and mobility u 77 = = 1.6⋅10 4 cm 2 /(V⋅s) in a pulsed magnetic field up to 200 Oe in the temperature range 2.8-300 К.The measurements show that the zero maxima ρ zz (Н) of low amplitudes occur in n-InAS at temperatures 4-35 К in the magnetic fields higher than 100 Oe. The dependence of the probability of scattering with a spin-flip on the temperature and magnetic field predicted in [1] is given as W р.с ≅ Т⋅Н 3/2 for the case of bulk crystals. The increase in the zero-maximum amplitude with temperature in a quantizing magnetic field is in qualitative agreement with the above dependence of the probability of electron scattering with a spin-flip on the temperature and magnetic field.

Samples of tricadmium diarsenide with MnAs nanogranules (44.7 mol % MnAs) are synthesized. The morphology of the samples is studied by X-ray phase analysis and electron microscopy. The electrical properties of tricadmium diarsenide with MnAs nanogranules are studied in a range of temperatures of 77-372 K. It is found that the voltammetric characteristics are symmetrical relative to the inversion of the voltage sign at this temperature, and their deviation from ohmicity at a certain threshold voltage and decrease in the region of ohmicity with the growth in temperature are determined by the increase in the breakdown probability in a field above 5 × 10 4 V/m.

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