FE-CR-HF-N AND FE-CR-TA-N SOFT-MAGNETIC THIN-FILMS

We have investigated the soft magnetic properties of new Fe-Cr-Hf-N an d Fe-Cr-Ta-N alloy films. Thin films with compositions in the range of Fe-2 similar to 8%Cr-0 similar to 1%Hf (or Ta)-5 similar to 10%N (in atomic %) were prepared by reactive sputtering in a nitrogen-containin g atmosphere. The films, most likely nanocrystalline, exhibit excellen t soft magnetic properties in the as-deposited condition without any p ost-deposition heat treatment, e.g., H-c similar to 1-2Oe (79.4-158.8A /m) and 4 pi M-s similar to 15-20kG. The magnetic properties are highl y anisotropic in the film plane as the easy-axis M-H loop is square an d the hard-axis loop is linear and closed, with the anisotropy field H -a=20-60Oe (1.59-4.77kA/m). The films exhibit excellent high frequency behavior even in the GHz frequency range which is attributed to the c ombination of high 4 pi M-s and relatively high H-a.