Effect of Neutron Irradiation of the Magnetic Properties and Degree of Order of Magnetic Metal Alloys

Sixty‐cycle sine current hysteresis loops have been made on thermally treated Permalloy type material both prior to and following neutron irradiation. In all cases the hysteresis loops of the irradiated alloys resembled the constricted loops characteristic of partially ordered ${\mathrm{Ni}}_3\mathrm{Fe}$ . The effect of the sample temperature during irradiation on the magnetic properties suggests that ordering results from diffusion of vacancies.