Thermal emission and pyroelectric current in manganese chalcogenides

Manganese chalcogenides, which are promising for the manufacture of thermoelements, are being studied. The current is measured in the temperature range of 80-500 K, in the absence of external voltage, which can be caused by a temperature gradient (thermopower), a change in electrical polarization (pyroelectric current), piezoelectric current (when the sample is deformed, a potential difference arises) or thermionic emission (thermal emission current) . Temperatures of current anomalies and their relationship with thermionic current and polarization current are found. A change in electrical polarization with temperature will cause a pyroelectric current. Compensation for excess electrical charge will result in local electrical polarization. Partial decompensation will cause the formation of an electric field in the sample. The critical temperatures for the disappearance of electric polarization were determined for different concentrations. In the region of concentration of thulium ions flowing through the lattice, the activation nature of the thermionic current was established and the activation energy was found. The pyroelectric current has a smaller value compared to the thermionic current. The current mechanism is determined by the emission of electrons from deep traps and the temperatures of the maximum thermionic current correlate with the temperatures at which IR absorption disappears. The electric current density and its value depend on the type of substituted rare earth element are calculated.