Precise measurements of ${\mathrm{YbFeO}}_3$ magnetization in the spin-reoirentation temperature interval are performed. It is shown that ytterbium orthoferrite is well described by the modified mean-field theory recently developed for ${\mathrm{ErFeO}}_3$. This validates the conjecture about the essential influence of the rare-earth ion’s anisotropic paramagnetism on the magnetization behavior in the reorientation regions of all orthoferrites with ${\Gamma }_4\to {\Gamma }_{24}\to {\Gamma }_2$ phase transitions.

• Received 2 March 2005

DOI:https://doi.org/10.1103/PhysRevB.72.174403