Field-enforced behaviour in 8.2/70/30 plzt

Abstract

The electro-optic behaviour in thin sections of 8.2/70/30 PLZT, thickness varying from 8 to 40 μm, is characterized in terms of a field-enforced phase transition. From X-ray measurements the field-enforced phase transition is shown to be from an, as yet, undetermined room-temperature, zero field structure to an orthorhombic phase which is isostructural with the orthorhombic phase of BaTiO₃. The behaviour of PLZT is then considered in the wider context of diffuse phase transitions. Evidence is presented suggesting that the anomalous behaviour seen in this system is not unique to PLZT; further, it is suggested that a new model involving three separate phases is required to fully explain the behaviour of such materials.