SOFT-MAGNETIC PROPERTIES OF FE-TM-C-N (TM-ZR, NB) NANOCRYSTALLINE FILMS

Soft magnetic properties of Fe-TM-C-N (TM: Zr, Nb) films, fabricated b y rf reactive sputtering in Ar+N-2 atmosphere, were investigated. The as-deposited films having mixed phases of amorphous and alpha-Fe or mo stly crystalline alpha-Fe phase showed nanocrystalline structure upon annealing. The best soft magnetic properties achieved in these films a re; H-c of 0.06 Oe, mu(eff) of 2750 (1MHz) and 4 pi M(s) of 16.8 kG in Fe-Zr-C-N film and H-c of 0.31 Oe, mu(eff) of 2100 (1MHz) and 4 pi M( s) of 15.5 kG in Fe-Nb-C-N film. The fine grained alpha-Fe structure, together with very fine TM(C,N) precipitates which were formed at an e arly stage of crystallization, is considered to be one of the main fac tors for the excellent soft magnetic properties. The Fe-Zr-C-N films e xhibit better soft magnetic properties than those of the Fe-Nb-C-N fil ms, which is considered to be due to the magnitude of the formation en thalpy.