Study of magnetic interactions in HoFeO3

The Ho-Fe and Ho-Ho interaction parameters are discussed in reference to optical Zeeman spectroscopic data and magnetization data on HoFeO₃. A molecular-field model is presented that incorporates these parameters in a systematic manner permitting accurate calculations of the ground-state pair Zeeman splitting constant and magnetization in the temperature region below about 60 °K. By applying the model to existing data the authors are led to the tentative conclusion that Ho-Fe exchange is dominantly antisymmetric. In addition, the effect of an applied magnetic field upon the reorientation transition is explored in detail. The interesting result obtained is that previously unexplained anomalies in the magnetization data are found to be attributable to a spin orientation, and that both the usual reorientation transition and the field-driven transition are contained in the same molecular-field interaction theory.