Variation of coercive force, isothermal remanent magnetization and magnetic memory in nickel with internal stress

The recovery process of cold-worked high purity nickel rods is followed by means of changes in the coercive force, isothermal remanent magnetization and memory of the metal. Activation energies are calculated by the cross-cut method using isothermal annealing curves based on the magnetic data. The activation energy in the early stages of annealing corresponds to that of vacancy migration. It increases as annealing continues and in the fairly well-annealed metal tends to the value for vacancy self-diffusion. The results lend general support to theories of coercive force which are based on dislocation models.