Specific features of the charge and mass transfer in a silver-intercalated hafnium diselenide

The specific features of the charge transfer in intercalated samples of Ag$_x$HfSe$_2$ have been studied for the first time by alternating current (ac) impedance spectroscopy. It has been found that relaxation processes in an ac field are accelerated with increasing silver content in the samples. The complex conductivity $(Y)$ shows a frequency dispersion described by power law $Y\sim\omega^s$, which is characteristic of the hopping conductivity mechanism. The Ag$_x$HfSe$_2$ compounds demonstrate shorter relaxation times as compared to those observed in hafnium diselenide intercalated with copper atoms, and this fact indicates that the charge carrier mobility in the silver-intercalated compounds is higher. The possibility of silver ion transfer in Ag$_x$HfSe$_2$ is confirmed by the measurements performed by the method of electrochemical cell emf.