The evolution of relaxor behavior in Ti4+ doped BaZrO3 ceramics

In this paper we have studied the relaxor behavior of BaZrxTi1-xO3 (0.50 <= x <= 0.80) ceramics. The relaxor behavior of BaZrxTi1-xO3 (BZT) solid solution is analyzed with respect to the increasing amount of Ti4+ rich polar regions in the nonpolar matrix of BaZrO3 which has a very low dielectric constant (similar to 27). The dielectric behavior of BaZrxTi1-xO3 ceramics is studied in the temperature range of 300-30 K. The relaxor behavior becomes more prominent with the increase of Ti4+ ion content, i.e., with increasing amount of the polar regions. The frequency dependence of the polar regions follows Vogel-Fulcher relation [Z. Phys. 22, 645 (1921); J. Am. Ceram. Soc. 8, 339 (1925)] with a characteristic cooperative freezing at a specific temperature. The dielectric behavior of BZT ceramics shows more electric field dependence with the increase in Ti4+ rich polar regions. (c) 2006 American Institute of Physics.