Influence of magnetic field on the dielectric characteristics in manganese sulfide substituted with thulium

Abstract

The properties of a solid solution of thulium-substituted manganese sulfide prepared by melting the initial pure samples of manganese sulfide and thulium sulfide are studied. X-ray diffraction analysis was carried out. The face-centered cubic lattice is determined, and the decrease in the intensity of the peaks is found. Dielectric permittivity was measured in the frequency range 102106 Hz and temperatures 300-500 K in magnetic fields up to 12 kOe in TmxMn1xS solid solutions (0 x 0,15). From the frequency dependence of the permittivity, the relaxation time and the relaxation mechanism of the dipole moments are found. The leakage current is excluded, and the contribution of migration polarization due to charges in the region with chemical phase separation is estimated. Die real and imaginary components of the permittivity of TmxMn1xS samples are described in the Debye model. The maximum of the imaginary component of the permittivity shifts towards higher frequencies upon heating, and the relaxation time is described by the Arrhenius function. Dielectric losses are caused by electron-phonon interaction. The frequency of the crossover from Debye relaxation to relaxation conduction associated with the absorption and emission of phonons is found. Die crossover frequency increases as the sample is heated according to a power law. In a magnetic field, the permittivity decreases and the largest change of 2.5 % is achieved at T = 450 K. At other temperatures, the magnetocapacitance does not exceed 0.5 %. The shift of the maximum of the imaginary component of the permittivity to low frequencies in a magnetic field leads to a change in the sign of dielectric losses from positive to negative. A qualitative difference in () is established in the vicinity of the concentration of thulium ion flow through the FCC lattice, where the permittivity is not described in the Debye model and there is no magnetocapacitance. The mechanism for reducing dielectric losses in a magnetic field is determined.