| Issue |
J. Phys. Colloques
Volume 49, Number C8, Décembre 1988
Proceedings of the International Conference on Magnetism
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|---|---|---|
| Page(s) | C8-1975 - C8-1976 | |
| DOI | https://doi.org/10.1051/jphyscol:19888895 | |
J. Phys. Colloques 49 (1988) C8-1975-C8-1976
DOI: 10.1051/jphyscol:19888895
DETECTION OF INDIVIDUAL PARTICLE SWITCHING DURING HYSTERESIS AND TIME DECAY IN Co-Cr THIN-FILMS
B. C. Webb et S. SchultzUniversity of California, San Diego and Center for Magnetic Recording Research, La Jolla, CA 92093, U.S.A.
Abstract
Discrete magnetization jumps of ~ 10-12 emu corresponding to the magnetization reversal of individual particles have been resolved in the hysteresis cycle of perpendicularly-oriented, columnar Co-Cr thin films. An experimental sensitivity of 4 x 10-14 emu has been achieved in microscopic Hall samples, containing only a few hundred magnetic columns, by using the anomalous Hall effect voltage generated by a current within the film itself to measure the magnetization. These data are the first experimental demonstration that the reversal of discrete magnetic units in a particulate media can be detected. The technique has been applied to determine the particle switching volumes and the temperature dependence of thermally activated magnetization time decay.