Temperature dependence of the dynamic electrical properties of Cu1+xMn1-xO2 (x = 0 and 0.06) crednerite materials

The conductivity spectrum, σ(f) follows the Jonscher universal law at each constant temperature. Based on the temperature and frequency dependencies of the electrical conductivity and using the variable-range-hopping (VRH) model, the frequency and temperature dependencies of the density of localized states near the Fermi level, N(EF), the hopping distance, R and the hopping energy, W were computed. The results show that at constant frequency, N(EF) does not depend on temperature for both samples. At constant temperature and frequencies up to 30 kHz, increasing the concentration of Cu ions leads to the decrease of R and W, whilst at high frequencies (over 100 kHz), R and W increase with the increase in the concentration of Cu ions.