Multiscale Phenomena in Bruggeman Composites

Authors

Ralph Skomski, University of Nebraska at LincolnFollow
Jiangyu Li, University of Nebraska-LincolnFollow
Jian Zhou, University of Nebraska-LincolnFollow
David J. Sellmyer, University of Nebraska-LincolnFollow

Date of this Version

2005

Comments

Published in Mater. Res. Soc. Symp. Proc. Vol. 851. Copyright © 2005 Materials Research Society. Used by permission.

Abstract

Mechanical, magnetic, and transport properties of arbitrary inhomogeneous composites are investigated by a Bruggeman-type mean-field approach. The theory yields materials parameters as functions of the volume fractions, geometries, and materials constants of the phases. Each system is described by a single response parameter g, which is equal to the percolation threshold of the composite. For macroscopic systems, the approach yields very simple expressions, but nanoscale and multiferroic effects yield relatively complicated corrections to g. In the respective cases, the parameter g depends on the length scale of the composite and has the character of a combination of magnetic, electric, and mechanical degrees of freedom.