Co-Cr Thin Films Deposited on Substrates with Island Structure

The effect of substrate morphology on the perpendicular anisotropy of Co-Cr films was studied. Co-Cr layers were deposited on top of Al-3 wt% Cu underlayers; the latter were of thickness 1.5 to 40 nm and were deposited at a substrate temperature of from 25 to 300°C. SEM photographs revealed an island structure for the Al-Cu films deposited at 300°C, while those deposited at 25°C had a flat surface. The ¿ ¿50 and Hkeff of Co-Cr films on Al-Cu underlayers deposited at 300°C were about 15° and 2 kOe respectively, while the figures when the Al-Cu layer was deposited at 25°C were under 10° and about 3 kOe respectively. The morphology of the Al-Cu underlayer thus greatly influenced the perpendicular anisotropy of the Co-Cr film.