PREPARATION OF SOFT-MAGNETIC AND THERMALLY STABLE FE-CO-TA-N TI MULTILAYERED FILMS BY SPUTTER-DEPOSITION/

Although the as-deposited Fe-Co-Ta:N single layer films with a thickne ss of 200 nm possessed large 4 pi M-s of about 16 kG, they revealed lo w mu(r). [Fe-Co-Ta:N/Ti](n) multilayers were prepared with the aim to improve soft magnetic characteristics of Fe-Co-Ta:N films. The [Fe-Co- Ta:N(SO nm)/Ti(10 nm)](4) multilayered films exhibited relatively high mu(r) of about 400 even in the as-deposited state. Furthermore, they exhibited better thermal stability of their soft magnetism. For exampl e, the multilayered films postannealed at T-A Of about 300 degrees C l ost only 20% of their moment, compared to as-deposited films, and main tained a relatively high mu(r). By contrast, a Fe-Co-Ta:N(200 nm) sing le layer film lost, at the same temperature, nearly 50% of its moment. X-ray diffractometry indicates that the postannealed multilayered fil ms did not include such paramagnetic zeta-Fe2N crystallites. It seemed that the Ti insertion layers worked as barrier layer for N diffusion to prevent the formation of such nitride crystallites. (C) 1997 Americ an Institute of Physics.