Coherency of magnetic switching in single and multilayered ferromagnetic films with strong out-of-plane anisotropy

The magnetization reversal in two metal-evaporated samples for magnetic rec ording, which display a strong out-of-plane anisotropy, has been studied by means of magneto-optic Kerr vector magnetometry, a technique that allows f or the determination (in three dimensions) of the magnetization vector dire ction as a function of the external field. One sample is a single CoNiO thi n film and the other is composed by three CoNiO layers. The results of the vector magnetometry analysis indicate that the magnetization of the two CoN iO samples rotates coherently out-of-plane, without domains formation, unti l the external field reverses and reaches a critical value H-cr. The compar ison and the detailed analysis of the results allowed us to evidence the di fferent degree of coherency of the magnetic switching in the two samples in vestigated and to relate it to their different structure. (C) 2001 American Institute of Physics.