FeTaN films with ultrafine grain structure

FeTaN films with moderate Bs of 14 kG and high resistivity of 100–150 μΩ cm have been investigated. Even with a low Ta incorporation of only 3 at. %, films with the above characteristics were obtained by using rf diode and dc magnetron sputtering. When the soft magnetic properties were optimized, only a body-centered-cubic α-Fe phase was found, and it had a significantly expanded crystal lattice. The films exhibited a nearly amorphous grain structure. It was found that low atomic mobility of the sputtered atoms was needed in order to promote formation of this phase.