Published in Journal of Applied Physics, Volume 49, Issue 3, March 1, 1978, pages 1815-1815.
NOTE: At the time of publication, the author Richard B. Frankel was not yet affiliated with Cal Poly.
The definitive version is available at https://doi.org/10.1063/1.324821.
This abstract may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following abstract appeared in Journal of Applied Physics.