Electrical and dielectric properties of HoMnO3 ceramics

The electrical and complex dielectric properties of ceramic hexagonal samples of HoMnO3 were investigated as functions of temperature and frequency. The resistivity and forbidden band width were determined, and the semiconductor transport properties were found in HoMnO3 ceramic samples. Two thermally activated dielectric relaxations were shown in the temperature dependence of the complex permittivity with the activation energies of 0.18 and 0.21 eV, respectively, and the respective peaks shifted to higher temperatures as the measuring frequency increased. The impedance spectroscopic plots were used to discern the intrinsic HoMnO3 grain and grain boundary effects on the dielectric responses.