The effect of substrate temperature on the magnetic properties of FeAlN thin films for recording heads

The soft magnetic properties of FeAlN films have been shown to be strongly dependent on the temperature of the substrate during deposition. Films of FeAlN were sputtered deposited onto Alumina/Titanium Carbide (ALTIC) ceramic substrates at substrate temperatures between 20 and 200/spl deg/C. In the range of 150 to 200/spl deg/C, the films display a well oriented easy axis with coercivities less than 1.5 Oe, and a hard axis coercivity of less than 1 Oe. Deposition at temperatures below 150/spl deg/C resulted in high coercivities and no in-plane anisotropy. This behavior is explained in terms of the temperature dependence of the formation of the /spl gamma/'-Fe/sub 4/N phase (identified by x-ray diffraction), which is necessary for the soft magnetic properties. A discussion of heating transients due to substrate thermal mass is also included.