COMPOSITION EFFECTS IN HIGH-DENSITY COPTCR MEDIA

The optimizatioin of the CoPtCr alloy for use in high density longitud inal magnetic recording is discussed. Low noise media can be obtained with a combination of high Cr concentration (22 at.%) and high deposit ion temperature. The results are consistent with a Cr segregation mech anism that provides reduction of exchange coupling without the need fo r a voided microstructure. The Curie temperature decreases significant ly 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.