Magnetic and structural properties of spin-reorientation transitions in orthoferrites

Magnetic and structural characteristics of ErFeO3, TmFeO3, and YbFeO3 single crystals were studied over a wide temperature range. Magnetic measurements found that the spin-rotation transitions in all crystals are well described by the earlier proposed theory with no fitting parameters. Additionally, they have shown the absence of the magnetic compensation point in TmFeO3 and a noticeable growth of the c-axis magnetization at low temperatures in TmFeO3 and ErFeO3. The x-ray measurements found no symmetry-lowering lattice distortions during the reorientation. Overall, the measurements cover a wide range of material parameters and demonstrate the generality of the modified mean field theory of the Gamma(4)->Gamma(24)->Gamma(2) orientation phase transitions in orthoferrites. (c) 2007 American Institute of Physics.