Spectroscopic and Magnetic Study of the Rare Earth Orthoferrites.

The objective of the study was to understand the magnetic behavior of the rare earth orthoferrites at an atomic level. The properties to be explained include a strongly temperature-dependent magnetization, a spontaneous magnetization which may differ by as much as two orders of magnitude from one rare earth orthoferrite to the next, and spin reorientation transitions, in which the spontaneous moment rotates from one crystalling direction to another as temperature is changed. The technique of exploration has been spectroscopic the energy levels of the rare earth ions and their variation with temperature and applied magnetic field are used to predict the macroscopic magnetic behavior of the whole material. Author