Mechanical activation of PbO-based relaxor ferroelectrics

Abstract

A novel synthesis technique mechanical activation was utilized to synthesize relaxor ferroelectrics of complex perovskite structure. Several unique phenomena, such as effects of the combination sequence of starting compositions, compositional inhomogeneities, and B-site order-disorder transformation, as well as interesting electrical properties, have been observed in the relaxor ferroelectrics derived from mechanical activation. Mechanical activation differs from thermal activation in terms of the stability of crystallinities, compositional homogeneities, structural order, and electrical properties for the materials derived. An explanation based on the framework of the competition between mechanical activation induced destruction in structural order and thermal activation that builds up the order has been provided to account for the order-disorder transformation triggered by mechanical activation. This was further simulated by a Monte-Carlo simulation algorithm, which provides an insight into the mechanism of B-site order evolution by mechanical activation.