Abstract
An account is given of investigations on the temperature dependence of the contribution from reversible processes to the magnetization of annealed and strained nickel wires This involves the measurement of reversible susceptibility κr over a range of field, and of temperature (-50° C. to +200° C.), and a rapid automatic method of recording (κr, H) curves has been developed. The effect of temperature on κr is discussed in relation to Becker's strain theory and reasons for the discrepancies are suggested. It is shown that the contribution of reversible processes to the total change in magnetization, integrated over the hysteresis cycle, increases with temperature and strain, from 15% for an annealed specimen at -50° C. to 85% for a strained specimen (17.1 kg. mm-2) at 150° C. The effect is not uniform over the whole cycle and in the region of the coercive field a considerable part of the change in magnetization must be attributed to irreversible processes.