Impedance spectroscopy of KTiOPO4 single crystal in the temperature range-100 to 100 °C

The electrical properties of a single crystal of KTiOPO4 was studied by impedance spectroscopy methods in the temperature range -100 to 100degreesC. The complex resistivity decreases rapidly with increasing temperature, and resistivity dispersion begins at a temperature of T-S=-80degreesC. The complex resistivity was fitted to the superposition of two Cole-Cole-type relaxations. The low frequency relaxation is associated with the electrode/crystal surface, while the high frequency relaxation is interpreted as resulting from ion migration in the bulk. It is believed that high frequency relaxation is related to ionic hopping conduction, which arises mainly from the jumping of K+ ions. The activation energies associated with hopping conduction are E(a)similar to0.21 eV above T-S and E(a)similar to0.11 eV below T-S .