Field and stress dependence of the irreversible magnetization changes in pure iron

Measurements of the irreversible magnetization changes accompanying the application and removal of stress to a sample of 99.99% pure iron have been made as a function of applied field and stress magnitude for both compressive and tensile stress. The fields for peak change have been compared with those for the peak difference MAN−MINI between the anhysteretic and initial magnetization curves and the field derivative of the magnetostriction. It is shown that at low tensile stress the magnetostrictive contribution is dominant, as found by Pravdin. At higher stress the wall pinning term is dominant, and the magnetization changes are proportional to MAN−MINI, in accordance with the Jiles–Atherton model.