MAGNETIC-ANISOTROPY AND MICROSTRUCTURE OF OBLIQUELY EVAPORATED CO CR THIN-FILMS/

Magnetic properties and the microstructure of Co/Cr thin films, prepar ed by oblique-incidence depositions have been investigated. The 5-100 nm thick Co films with 200 +/- 50 nm thick Cr underlayers are found to have an in-plane magnetic anisotropy with the easy axis transverse to the incident plane. The coercivity H-c and the in-plane magnetic anis otropy energy K-u,K-in-plane are dependent on both the incident angle and the Co layer thickness. The highest H-c (240 kA/m) and the highest K-u,K-in-plane (1 X 10(5) J/m(3)) values are obtained when the incide nt angle is 70 degrees and the Co layer is 10 nm thick. The Co layer c onsists of anisotropic shape clusters where the neighboring Co grains along the incident plane are physically separated by the surface rough ness of inclined Cr columnar grains, while the neighboring Co grains t ransverse to the incident plane are connected. The temperature depende nce of the K-u,K-in-plane suggests that the Co layer has a weak prefer red c-axis orientation transverse to the incident plane. The contribut ion of the crystalline anisotropy to the in-plane magnetic anisotropy is shown to be comparable to that of the shape anisotropy of the Co cl usters.