From: David Vanderbilt <dhv@physics.rutgers.edu> Date: Tue, 23 Jun 1998 17:54:23 GMT (11kb)
Authors:
L. Bellaiche,
David Vanderbilt (Department of Physics and Astronomy, Rutgers University)
Comments: 4 pages, two-column style with 1 postscript figure embedded. Uses
REVTEX and epsf macros. Also available at
this http URL
Subj-class: Materials Science
We present a simple ionic model which successfully reproduces the various types of compositional long-range order observed in a large class of complex insulating perovskite alloys. The model assumes that the driving mechanism responsible for the ordering is simply the electrostatic interaction between the different ionic species. A possible new explanation for the anomalous long-range order observed in some Pb relaxor alloys, involving the proposed existence of a small amount of Pb^4+ on the B sublattice, is suggested by an analysis of the model.