Perovskite and aurivillius: Types of ferroelectric metal oxides

Abstract

Ferroelectric oxides could be classified into four structure types: perovskite, pyrochlore, tungsten-bronzes, and layer-type bismuth compounds (so-called Aurivillius). Geometrical packing of ions in the lattice is an important factor that determines the structure type and possible application. An overview of perovskite and Aurivillius ferroelectric metal oxides is given. The perovskite structure can be considered as a three-dimensional framework of BO6octahedra, but it can also be regarded as a cubic close packed arrangement of A and O ions, with the B ions filling the interstitial positions. The other most frequently investigated compounds are with Aurivillius structure that is formed by alternating (Bi2O2)2+ and (An-1BnO3n+3)2- layers, the latter is with pseudo-perovskite structure. These structures possess capability to host ions of different size in their lattices enabling the tailoring of the material properties. The list of possible dopant incorporations and its influence on the structure and microstructure modifications for their wide application are presented.