Postprint version. Published in Applied Physics Communications, Volume 8, January 1, 1988, pages 117-126.
NOTE: At the time of publication, the author R.B. Frankel was not yet affiliated with Cal Poly.
1988 Taylor & Francis.
This is an electronic version of an article published in Applied Physics Communications. The definitive version is available at http://www.taylorandfrancis.com.