Magnetomechanical coupling, ΔE effect, and permeability in FeSiB and FeNiMoB alloys

Measurements of magnetomechanical coupling, ΔE effect, and relative permeability have been made as a function of bias field and annealing temperature and time in transversely annealed samples of Metglas R a) alloy 2605S‐2 (Fe78Si9B13), Metglas alloy 2605S‐3 (Fe79Si5B16), and Metglas alloy 2826MB (Fe40Ni38Mo4B18). Annealing temperatures and times were varied from 300 to 450 °C and 15 to 60 min, respectively. The bias field which generates the largest coupling factor in these alloys is less than 1 Oe. From an application point of view, this low optimum field has a distinct advantage in power requirements over the 11 Oe field required for Metglas alloy 2605CO1 but the low field requirement is a marked disadvantage when considering bias field stability. That is, a 0.5 Oe change in field can result in greatly reduced coupling in the present alloys versus a very small change in 2605CO.