THE EFFECT OF ANNEALING ON MOMENT DENSITY AND PHASE FORMATIONS IN FE-N FILMS

Fe-N films have been prepared by argon-nitrogen reactive RF sputtering at a total pressure of 6 mTorr, an argon flow rate of 100 standard cubic centimeters per minute (sccm) and a nitrogen flow rate R of 0 to 30 sccm. For R less-than-or-equal-to 15 sccm, little changes in phase structure and moment (DELTAsigma(S) less-than-or-equal-to 6%) were seen for annealing temperature T(A) less-than-or-equal-to 300-degrees-C. Above 300-degrees-C, changes in the phase structure and moment (DELTAsigma(S) greater-than-or-equal-to 12%) were observed. For R=30 sccm, no phase changes were observed at all annealing temperatures and the moment was found to be constant (DELTAsigma(S) less-than-or-equal-to 5%). The phases ob-served by X-ray and transmission electron diffraction depended on R and included alpha-Fe(N), Fe16N2 and Fe4N. These data could be correlated with the moment. The Curie temperature of Fe4N was 180 approximately 510-degrees-C in good agreement with previous result.