Magnetic domain structures in CoCr films studied by Lorentz microscopy

Magnetization distribution and behavior of magnetization in CoCr sputtered films of various thickness are studied by high-resolution Lorentz microscopy. The perpendicular component of magnetization increases with increasing film thickness, corresponding to the increase in the Q-value. The dominant mechanism of magnetization reversal changes from the domain wall displacement mode in the 200 Å thick film to the rotational mode in the 1000 Å thick film. In the 600 Å thick film, elongated domains with a kind of cross-tie walls are formed perpendicular to an AC demagnetizing field in the film plane.