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

Document Type

Article

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.}