Magnetic properties and magnetization process in CoCr films sputtered on low-temperature substrates

Saturation magnetizations, M-T curves and Curie temperature are measured for the CoCr films sputtered on polyimide films of 27°C. Their properties resemble those of CoCr bulk materials because of the homogeneous morphology. Furthermore, the films with a highly oriented c-axis show perpendicular hysteresis loops have a sharp shoulder and low coercivity. In these films, therefore, the nucleation and the strip-out of the reversed domains are clearly observed by the Bitter method when the external field is decreased from the saturation field. The domain pattern and the magnetization process can be interpreted accurately by the domain theory assuming the domain wall motion.