MAGNETOSTRICTION AND THIN-FILM STRESS IN HIGH MAGNETIZATION MAGNETICALLY SOFT FETAN THIN-FILMS

Domain structures in thin-film heads can be significantly influenced b y magnetoelastic anisotropy. In this study we have undertaken systemat ic measurements of magnetostriction and stress in as-deposited and ann ealed states in FeN and FeTaN single-layer thin films with varying nit rogen contents. Magnetostriction was positive for FeN films, increased with increasing nitrogen content, and shifted toward negative values after annealing. Stress in as-deposited FeN films was tensile and decr eased (became more compressive) with increasing nitrogen content. Anne aling the FeN films resulted in significant stress relief. By contrast , magnetostriction was found to be negative for simple FeTa (zero nitr ogen) and increased linearly with increasing nitrogen content to posit ive values. The magnetostriction in FeTaN did not change significantly after annealing at 200 and 250 degrees C. FeTaN film stresses were co mpressive in the as-deposited state and increased in magnitude (became more compressive) with increasing nitrogen content. After annealing t hese stresses were relieved slightly. Ta has been found to be very eff ective in enhancing the thermal stability of the FeN films. (C) 1996 A merican Institute of Physics.