2009/01/01 by Daniel Freedman, Daniel A. Freedman, Freedman, Daniel A. +2
Engineering · Materials Science · Physics and Astronomy · #Ferroelectric and Piezoelectric Materials #Multiferroics and related materials #Perovskite Materials and Applications #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.0901.0157
18 pages, 12 figures, 6 tables
arxiv created 2009/01/01 · arxiv updated 2009/12/01
This work presents the most detailed and extensive theoretical study to date of the structural configurations of Ruddlesden-Popper (RP) phases in antiferrodistortive (AFD) perovskites and formulates a program of study which can be pursued for RP phases of any AFD perovskite system. We systematically investigate the effects of oxygen octahedral rotations on the energies of RP phases in AFD perovskites (An+1 Bn O3n+1) for n = 1...30, providing asymptotic results for n --> infinity that give both the form of the interaction between stacking faults and the behavior of such stacking faults in isolation. We find an inverse-distance interaction between faults with a strength which varies by as much as a factor of two depending on the configuration of the octahedra. We find that the strength of this effect can be sufficient to (a) stabilize or destabilize the RP phase with respect to dissociation into the bulk perovskite and the bulk A-oxide and (b) affect the energy scales of the RP phase sufficiently to constrain the rotational states of the octahedra neighboring the stacking faults, even at temperatures where the octahedra in the bulk regions librate freely. Finally, we present evidence that the importance of the octahedral rotations can be understood in terms of changes in the distances between oxygen ions on opposing sides of the RP stacking faults.