An anomalous magnetoelastic effect in nickel

A new magnetoelastic effect in nickel has been found that led us to modify some current theories about magnetization processes in weak fields. A longitudinal compression in Ni decreases its magnetization instead of increasing it. This behavior can be explained by a weak field spin rotation model, as opposed to the usual domain-wall motion theory. The important role played by residual stresses has also been taken into account, and a method for evaluating them is suggested.