Visualization of Bi3+ off-centering in the average cubic structure of (Ba0.70Bi0.30)(Ti0.70Fe 0.30)O3 at the electron density level

Abstract

We present here evidence for the off-centering of Bi3+ symmetrically distributed along the six 100 directions of a pseudocubic composition (Ba0.70Bi0.30)(Ti0.70Fe 0.30)O3 at the electron density distribution level. We also calculate the strength of covalent bonding between the oxygen (O 2-) anions with A-site (Ba2+/Bi2+) and B-site (Ti4+/Fe3+) cations, which provides evidence for the stabilization of average cubic symmetry. We believe that Bi3+ positional disorder may be ubiquitous in all the lead free piezoceramic solid solutions of the type (Ba1-xBix)(Ti1-xMe x)O3, where Me = Fe3+, Sc3+, Al 3+, (Mg1/2Ti1/2)3+, and (Zn 1/2Ti1/2)3+. © 2013 AIP Publishing LLC.