Department of Physics Papers
Document Type
Journal Article
Date of this Version
5-18-2012
Publication Source
Physical Review B
Volume
85
Start Page
174107-1
Last Page
174107-22
DOI
10.1103/PhysRevB.85.174107
Abstract
The list of possible commensurate phases obtained from the parent tetragonal phase of Ruddlesden-Popper (RP) systems, An+1BnC3n+1 for general n due to a single phase transition involving the reorienting of octahedra of C (oxygen) ions is reexamined using a Landau expansion. This expansion allows for the nonlinearity of the octahedral rotations and the rotation-strain coupling. It is found that most structures allowed by symmetry are inconsistent with the constraint of rigid octahedra, which dictates the form of the quartic terms in the Landau free energy. For A2BC4 our analysis allows only 10 of the 41 structures which satisfy the general symmetry arguments of Hatch et al. [Phys. Rev. B 39, 9282 (1989)]. The symmetry of rotations for RP systems with n>2 is clarified. Our list of possible structures for general n excludes many structures allowed in previous studies.
Recommended Citation
Harris, A. (2012). Landau Theory of Tilting of Oxygen Octahedra in Perovskites. Physical Review B, 85 174107-1-174107-22. http://dx.doi.org/10.1103/PhysRevB.85.174107
Date Posted: 12 August 2015
This document has been peer reviewed.