Ferroelectricity in Perovskitelike NaCaF₃ predicted ab initio

Authors

P. J. Edwardson, U. S. Naval Research Laboratory, Washington, D. C.
L. L. Boyer, U. S. Naval Research Laboratory, Washington, D. C.
R. L. Newman, University of Nebraska - Lincoln
D. H. Fox, University of Nebraska - Lincoln
John R. Hardy, University of Nebraska - LincolnFollow
J. W. Flocken, University of Nebraska, Omaha, Nebraska
R. A. Guenther, University of Nebraska, Omaha, Nebraska
Wai-Ning Mei, University of Nebraska at OmahaFollow

Date of this Version

5-1-1989

Comments

Published in Physical Review B Volume 39, Number 13, 1 May 1989. Copyright © 1989 The American Physical Society. Used by permission.

Abstract

The ability of zero-stress simulations, using Gordon-Kim pair potentials, to describe the structures and transformations of known fluoride-based perovskites is demonstrated for the case of KCaF₃. When K⁺ is replaced by Na^{+ a new ferroelectric crystal isomorphous with LiNbO₃ is predicted. The equivalent relationships of the ferroelectric lithium niobate structure with the perovskite and antiperovskite structures are examined. A polarization of 21 jµC/cm2 at room temperature and a transition temperature of 550 K are predicted for NaCaF₃. Surface effects are examined in simulations of a 1080-ion cluster.}