A statistically designed investigation of substrate effects on CoCr thin films for perpendicular magnetic recording

The properties of sputter deposited CoCr films vary significantly as a function of sputtering conditions and substrate. Mathematical expressions for the dependence of the film coercivity and the magnetic orientation ratio on the sputtering parameters have been derived. The variation in film structure from substrate to substrate has been observed clearly by electron microscopy, making use of improved sample preparation techniques. Columnar growth of hcp films is found to begin much earlier in the growth of the film when the substrate is glass, and much later when the substrate is metallic.