MAGNETOSTRICTION OF FE-AL-SI ALLOY SPUTTERED FILMS.

Magnetostriction measurements were made by the optical cantilever method for Fe-Al-Si (1 approx. 6wt% Al, 5. 5 approx. 9. 5 wt% Si, bal. Fe) alloy films prepared by dc magnetron sputtering. The magnetostriction, lambda , for the films with approx. 90 wt% Fe concentration changes its value remarkably with annealing higher than 300 degree C. This annealing temperature at which sudden decrease of lambda takes place corresponds well to the ordering temperature in the films. Two different film concentration regions, 5. 7 wt% Al-9. 0 wt% Si-bal. Fe and 4. 2 wt% Al-8. 0 wt% Si-bal. Fe, at which the soft magnetic properties (Hc approximately equals 0. 4 Oe, mu eff greater than 1000 at 5 MHz) are realized, were found to lie at about lambda approximately equals 2 multiplied by 10** minus **6. The difference of concentration dependences of lambda +ZZfor the films fabricated by vacuum evaporation and by sputtering are discussed.