Apparatus for magnetic measurements under biaxial stress

Apparatus for observing the effects of biaxial stress on discs of soft ferromagnetic materials is described. The apparatus is optimized for fundamental studies of stress-induced magnetization changes and the stress dependence of hysteresis parameters. Out-of-plane anisotropy is minimized by the use of a novel method of measuring the magnetization, based on a Hall probe near the surface. The system currently operates with applied fields up to 30 kA/m and stress magnitudes in orthogonal directions up to 50 MPa. Illustrative results for the isofield stress-induced irreversible magnetization changes in pure iron are presented in the form of contour plots.