Spontaneous (zero-field) relaxor–to–ferroelectric-phase transition in disordered Pb(Sc1/2Nb1/2)O3

Abstract
Recently, it has been shown that, upon cooling, disordered Pb(Sc1/2Ta1/2)O3 ceramics transform spontaneously from a relaxor state to a ferroelectric state when processed in a manner that suppresses lead vacancies. If lead vacancies are present, the spontaneous ferroelectric transition is suppressed and the ceramics exhibit the usual relaxor behavior in a wide temperature range. It is shown that disordered Pb(Sc1/2Nb1/2)O3 ceramics have a similar nature: When produced in a manner that does not eliminate lead vacancies, they exhibit normal relaxor behavior. However, if stoichiometry is tightly controlled, disordered Pb(Sc1/2Nb1/2)O3 transforms spontaneously (under zero‐bias field) from a relaxor into a normal ferroelectric upon cooling.