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 featherlike 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.<
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