ΔE effect and magnetomechanical coupling factor in Fe 80 B 20 and Fe 78 Si 10 B 12 glassy ribbons

Field annealing experiments on amorphous Fe 80 B 20 ribbon (Metglas 2605) and amorphous Fe 78 Si 10 B 12 ribbon (Tsuya, Tohoku University) are reported. The maximum magnetomechanical coupling constant, k , and change in Young's modulus, ΔE/E 0 found in Fe 80 B 20 were 0.64 and 0.87, respectively, for an anneal of 376° for 6 min in a field of 2.0T. The maximum k for Fe 78 Si 10 B 12 was found to be 0.82, following a similar anneal at 373°C. This is higher than 0.75 reported by Tsuya and Arai for Fe 78 Si 10 B 12 , previously the highest known for any material.