Soft Magnetic Properties and Domain Structure of Fe-N-O Thin Films for Thin Film Head Applications

The soft magnetic properties and domain structure of Fe-N-O films were examined for the purpose of thin film head application, as a function of nitrogen and oxygen partial pressure during sputtering. The introduction of a very small amount of oxygen along with nitrogen can effectively reduce the grain size of Fe, resulting in a decrease in the coercivity. Fe-N-O films with a high saturation flux density (20 kG), low coercivity (0.6 Oe) and large permeability (4000 at 1 MHz) can be obtained by sputtering in a mixture atmosphere of nitrogen and oxygen. Even though the domain structure of the Fe-N-O film contains large triangle domains, it can be improved prominently by forming an amorphous Co-Zr underlayer. In conclusion, Fe-N-O/Co-Zr double-layered films are possible for thin film head applications.