Approaches to reduce temperature coefficient of coercivity of high-density recording media

The magnitude of temperature coefficient of coercivity (|dH_C /dT|) of high-density recording media increases with decreasing media thickness and dilution of the Co in the interior of the grains by Cr or other substitutions. A reduction in magnetic anisotropy with temperature increases |dH_C/dT| whereas a decrease in magnetization compensates for such change. Some approaches such as better Cr segregation, or utilizing a magnetic bilayer with the initial layer having a lower Curie temperature can be used to minimize |dH_C /dT|