DOMAINS AND DOMAIN NUCLEATION IN MAGNETRON-SPUTTERED COCR THIN-FILMS

The magnetic domain configurations in magnetron-sputtered CoCr thin films have been examined by Lorentz transmission electron microscopy. The thinnest (10 nm) films display in-plane 180-degrees domain walls, while thicker (50 nm) films exhibit out-of-plane "dot"-type domain structures. The "dot" domains were observed even in films that had not yet developed a columnar morphology. Intermediate thickness films show a "feather-like" contrast, indicating that both in-plane and out-of-plane magnetization components are present. Magnetization reversal is seen to occur by domain wall motion in films displaying in-plane anisotropy and by rotation for perpendicular anisotropy films. Intrinsic film stress was found to play a major role in determining the preferred magnetization direction, and thus the resulting magnetic domain configurations.