Spin-reorientation transitions in Er, Tm and Yb orthoferrites: magnetic and structural properties.

Magnetic and structural characteristics of ErFeO$_3$, TmFeO$_3$ and YbFeO$_3$ 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 TmFeO$_3$, and a noticeable growth of the c-axis magnetization at low temperatures in TmFeO$_3$ and ErFeO$_3$. 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 $\Gamma_4 \to \Gamma_{24} \to \Gamma_2$ orientation phase transitions in orthoferrites. // L. T. Tsymbal {\em et al.}, J. Appl. Phys {\bf 101}, 123919 (2007).