Magnetostriction and the magnetic phases of single crystal terbium-50% holmium

The c-axis magnetostriction, λ_c, has been measured in terbium-50% holmium in fields up to 2 T between the Néel and Curie temperatures. The magnitude and temperature dependence of λ_c are similar to those previously reported for dysprosium. Detailed strain measurements between the critical field, H_c, which destroys the antiferromagnetic spiral spin structure and the field induced ferromagnetic phase show that the extent of an intermediate fan phase is more limited than previous theoretical analyses have predicted. The difference between the experimental data and strains calculated from theory can be explained only in part by the influence of magnetostry calline anisotropy.