Effect of Quenched-in Vacancies on the Weak Magnetization of Nickel

The change in magnetization in weak magnetic field of nickel quenched from high temperatures was measured means of a sensitive astatic magnetometer, and it was found that the magnetization increased nearly proportionally to the logarithm of the time elapsed after quenching. It is shown that the effect can be analyzed phenomenologically one of formal theories proposed on the magnetic after effect. On the other hand, the formation energy of the vacancies was estimated roughly to be 1.4 eV, which showed a good agreement with the results of other observations. It is, therefore, quite likely that the observed change in magnetization is entirely due to the annihilation of the frozen-in vacancies.