HIGH-FREQUENCY PROPERTIES OF FE-CR-TA-N SOFT-MAGNETIC FILMS

High frequency magnetic properties of a new, soft magnetic Fe-Cr-Ta-N alloy film have been investigated. Thin films with a composition of Fe -4.6% Cr-0.2% Ta-7.4% N (in atomic %) were prepared by reactive sputte ring in a nitrogen-containing atmosphere. The films, most likely nanoc rystalline, exhibit excellent soft magnetic properties in the as-depos ited condition without any post heat treatment, e.g., H-c as low as 1. 2 Oe (95.3 A/m) and 4 pi M-s similar to 20 kG. The easy-axis M-H loop is square. The hard-axis loop is linear and closed, with the anisotrop y field H-a = 20-100 Oe (1.59-7.95 kA/m). By virtue of their high 4 pi M-s and relatively high H-a, these soft magnetic films exhibit high p ermeability and low loss in the GHz frequency range with the undesirab le ferromagnetic resonance interference suppressed to beyond 2 GHz. (C ) 1997 American Institute of Physics.