Molecular field coefficients of terbium, dysprosium and holmium iron garnets

Molecular field coefficients related to the rare earth iron interactions are determined in rare earth iron garnets TbIG, DyIG, HoIG. An analysis of the temperature dependences of the single crystals magnetization and of the susceptibilities shows that these parameters are temperature dependent in 70-300K range. Discontinuities of nacand ndcoccuring at the compensation temperature are found. Nevertheless, the molecular field acting on the rare earth ions is continuous at Tcomp. Comparisons with previous determinations are given.