Synthesis and characterization of lead-free K 0.5Bi 0.5TiO 3 ferroelectrics by sol–gel technique

Abstract

A kind of novel lead-free ferroelectrics, potassium bismuth titanate, K 0.5Bi 0.5TiO 3 (KBT), has been prepared by the sol–gel process. The amorphous dried gels were first transformed into Bi 2Ti 2O 7 phase at low heat-treated temperature and as the temperature increased to 700 °C, only pure KBT phase can be observed and there was no evidence of second phase. KBT ferroelectric ceramics were fabricated from the natural sintering of 700 °C-treated powders, which have a particle size of 100–200 nm. The KBT ceramics sintered at 1050 °C showed typical characteristics of relaxor ferroelectric, and the dielectric properties were better than that prepared by a solid-state reaction method.