Dielectric behaviour of cobalt titanium oxide.

The complex dielectric properties of CoTiO3 ceramics were investigated as functions of temperature (130 K [?] T [?] 430 K) and frequency (100 Hz [?] f [?] 100 kHz). Two thermally activated dielectric relaxations were observed. TiO2 addition and annealing treatments were used to modify the behaviour of these relaxations. It was found that the low-temperature relaxation can be greatly enhanced by the addition of TiO2. Annealing in N2 at 800 °C for 2 h eliminates the low-temperature relaxation but largely strengthens the high-temperature relaxation, whereas annealing in O2 at 800 °C for 2 h causes the opposite effects. It was suggested that the low-temperature relaxation can be related to the dipolar effect induced by charge-carrier hopping motions while the high-temperature relaxation might be ascribed to the defect dipolar polarization. [ABSTRACT FROM AUTHOR]