Al COMPOSITION DEPENDENCE OF THE MAGNETIC PROPERTIES OF Co-Fe-Al-N FILMS

High saturation magnetic flux density Co-Fe-Al-N films were prepared by rf sputtering in a mixed Ar and N2 gas atmosphere with the Al content as a parameter. 1 at.% Al films showed a high coercive force (Hc) of more than 2000 A/m, a grain size of about 30 nm and an fcc (100) preferred orientation. 3-5 at.% Al films showed good softness with an Hc of less than 80 A/m. a fine grain size of about 10 nm and the disappearance of the fcc (100) preferred orientation. 8 at.% Al films showed slightly higher Hc than that of 3-5 at.% Al films in spite of the same fine grain size as or less than that of 3-5 at.% Al films. The lattice constant did not change by increasing the Al content to 8 at.%. No AlN was detected by XPS and diffraction patterns for 4 at.% Al films, though it was detected for 8 at.% Al films.