Quadruple superstructure with antiferroic ionic displacements in B i1 -xS mxFe O3
Abstract
Crystallographic and morphologic features of quadruple and double superstructures in B i1 -xS mxFe O3 with 0 ≤x ≤0.4 0 were investigated by x-ray powder diffraction and transmission electron microscopy. The presence of a quadruple superstructure accompanied by antiferroic ionic displacements was found near the morphotropic phase boundary between the R 3 c phase (0 <x <0.1 0 ) and the Pnma phase (0.25 ≤x ≤0.4 0 ). The quadruple superlattice phase coexists with a ferroelectric R 3 c phase at x =0.15 . These superstructures were found to originate from the freezing of multiple phonon modes related to transverse wave ionic displacements. These findings provide further insight towards understanding the complexity of rare-earth-doped BiFe O3 .
- Publication:
-
Physical Review B
- Pub Date:
- July 2019
- DOI:
- 10.1103/PhysRevB.100.024105
- Bibcode:
- 2019PhRvB.100b4105H