Influence of the concentration of intercalated atoms and temperature on relaxation processes upon charge transfer in Cu$_x$HfSe$_2$ compounds

The temperature dependences of impedance spectra of the intercalation compounds Cu$_x$HfSe$_2$ ($x$ = 0.1, 0.2) in the frequency range from 0.1 Hz to 5 MHz have been obtained for the first time. It has been shown that the characteristic times of relaxation processes decrease with an increase in the concentration of copper in the samples, as well as with an increase in the temperature. This is accompanied by a shift of the frequency dispersion of the complex conductivity toward the higher frequency range. The frequency and temperature dependences of the dielectric loss tangent for the studied samples are characteristic of losses due to the through electrical conductivity.