The Coercivity of Cobalt-Platinum

The magnetic properties of the 50 atomic per cent cobalt-platinum alloy are quite exceptional and make it one of the most powerful permanent magnet materials available. In this article the author reviews the accepted mechanisms for high coercivities in an attempt to establish which is the more likely to apply to equiatomic cobalt-platinum in its hard magnetic condition. Some original studies are also presented, and some suggestions are put forward for the further development of this material.