Dielectric behavior of TiO_2 ceramic prepared by plasma activated sintering

摘要

Rutile-phase TiO_2 ceramic was rapidly fabricated by plasma activated sintering (PAS) at 650-850 °C for 3 min under 30 MPa. The temperature and frequency dependences of the dielectric properties (dielectric constant and dielectric loss) for the dense TiO_2 ceramic were investigated, and the dielectric behavior was briefly discussed. It was demonstrated that extraordinarily high dielectric constant (2-5 xlO4) was observed in the whole experimental ranges of -160 to 200 ℃ and 1 kHz-1 MHz. Moreover, the dielectric loss kept a relatively normal level, however, its temperature and frequency dependences were markedly different with those of the rutile-phase TiO_2 preforms. The unusual dielectric behavior was related with the particular dielectric polarizations of the TiO_2 ceramic and its dominant form of loss under different conditions.