Magnetization Process in High Magnetic Fields for Fe and Ni in Their Critical Regions

Abstract

Magnetization curves were measured in high pulsed magnetic fields above 100 kOe for Fe and Ni just below and above their Curie points. For both Fe and Ni, a linear relationship between M² and H/M holds in the high field region above 70 kOe. From the linear parts, Landau factors in a phenomenological equation and the critical exponents were determined without being affected by spin clusters. For Fe, the estimated critical exponents are consistent with those expected from the molecular field theory, which are the same results as for Ni. Furthermore, theoretical magnetization curves were calculated by means of the Green function method in order to compare with the experimental results. Both the shapes of calculated curves and their Landau factors are quite similar to the experimental ones.