Composition effects in high density CoPtCr media

The optimization of the CoPtCr alloy for use in high density longitudinal magnetic recording is discussed. Low noise media can be obtained with a combination of high Cr concentration (22 at.%) and high deposition temperature. The results are consistent with a Cr segregation mechanism that provides reduction of exchange coupling without the need for a voided microstructure. The Curie temperature decreases significantly at 25 at.% Cr preventing further increase in the Cr concentration. Pt is added to the alloy to increase coercivity with little effect on other recording properties.<
>