Perovskite nanocrystallite of PMN-based ferroelectrics by mechanical activation

Abstract

Nanocrystallites of Pb(Mg1/3Nb2/3)O3(PMN)-based perovskite structure are formed at room temperature by mechanical activation of the constituent oxides. The activation-triggered occurrence of perovskite nanocrystallites in the oxide compositions proceeds via a process involving nucleation and subsequent growth of perovskite crystallites with increasing degree of mechanical activation. This is fundamentally different from the one or more interfacial reactions and diffusions responsible for a thermally activated solid state reaction occurring at an elevated temperature. Nucleation occurs in a highly activated state, where a degree of amorphization has taken place, and the subsequent growth proceeds as a result of the constant collisions and rearrangement of perovskite nuclei.