Wear resistance, mechanical strength and microstructure on sputtered CoCr perpendicular media

Wear resistance for sputtered CoCr perpendicular recording media has been investigated. Wear resistance and mechanical strength (tensile strength and Young's modulus) have been measured for CoCr (0-33 at% Cr) films deposited under various sputtering conditions. Furthermore, their correlations to CoCr film microstructures have been studied. The wear resistance on the CoCr films strongly depends upon the mechanical strength, and their relationship can be explained in terms of Archard's adhesive wear theory. Wear resistance and mechanical strength for CoCr (5-33 at% Cr) films decrease steeply at high sputtering Ar pressure. However, those for pure Co films are independent from sputtering pressure. Microstructure analyses for CoCr and pure Co films indicate that a main factor reducing the wear resistance and the mechanical strength is Cr segregation in the CoCr films.