Stress-Annealing Induced Anisotropy in FeCrCuNbSiB Nanocrystalline Wires

Abstract

A few of amorphous wires of compositions Fe73.5-xCrxCu1Nb3Si13.5B9 (x = 0, 3 and 7) were submitted to current-annealing under the application of tensile stresses (s = 0 – 228 MPa). The measurement of longitudinal hysteresis loops, M(H) , was performed on the samples, from which the stress-annealing induced transverse anisotropy constant, K, were determined. We found that the magnitude of K and the s - sensitivity of K, dK/ds, decrease with increasing the amount of Cr. These results have been explained by the Herzer’s back-stress theory by considering the reduced magnetostriction with increasing the amount of Cr. Additionally, an abnormal disappearing K for large-stress-annealed samples of x = 0 was observed and it was discussed by a few of possible mechanisms.