Fe and FeCo Thin Films Prepared by Ar+N2 Ion-Beam Sputtering

The characteristics of ferromagnetic metal nitride thin films as potential magnetooptic recording media fabricated by ion-beam sputtering were studied, with special emphasis on factors relating to the perpendicular magnetic anisotropy. The transmittance of films was found to be related to the c-axis orientation of the Fe and FeCo nitride. The FeCo nitride thin films had a large Faraday rotation of θ=7.7 deg/μm at 780 nm. Fe and FeCo nitride thin films were found to have a high corrosion resistance in NaCl water solution. TEM observations of cross-sections of ferromagnetic metal nitride thin films revealed a columnar microstructure composed of an amorphous phase and a crystalline phase, with grains of 10 nm or less in diameter.