Abstract:
The dynamic characteristics of the Sm$_x$Mn$_{1-x}$S solid solution are studied by impedance spectroscopy in the frequency range of 10$^2$–10$^6$ HZ, IR spectroscopy in the temperature range of 80–500 K. The relaxation time of current carriers and its dependence on temperature from the impedance hodograph are found. A correlation between the temperatures of anomalies in the transport characteristics and the frequency of softening of the IR vibration mode of the octahedron is established. The frequency dependence of the activation energy and the critical frequency of the transition from semiconductor to metallic type of conduction are found. The reversal of the sign of the magnetoimpedance and magnetoresistance on alternating current in Sm$_x$Mn$_{1-x}$S upon heating and their maximum in the region of the electronic structural transition are determined. The magnetoimpedance in the paraphase is explained by the change in the permittivity in a magnetic field.
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