First principles prediction of a morphotropic phase boundary in the Bi(Zn1/2Ti1/2)O-3-(Bi1/2Sr1/2)(Zn1/2Nb1/2)O-3 alloy

作者：Cooper Valentino R^*; Henry Asegun S; Takagi Shigeyuki; Singh David J

来源：Applied Physics Letters, 2011, 98(12): 122903.

DOI：10.1063/1.3570626

The magnitude and direction of polarization within alloys of the tetragonally distorted Bi(Zn1/2Ti1/2)O-3 (BZT) and the rhombohedrally oriented (Bi1/2Sr1/2)(Zn1/2Nb1/2)O-3 are explored using density functional theory. For compositions with >= 50% of BZT, we find that the polarization is mainly in the [001] direction. Conversely, for low concentrations of BZT the polarization is rhombohedrally oriented. Based on these results we propose a phase diagram with a monoclinic phase that appears when the BZT concentration is roughly 50%. At this concentration, the material may have a useful piezoelectric response.

• 出版日期2011-3-21