The magnetic interactions between rare-earth and Fe ions in hexagonal rare-earth ferrites $\left(h\text{−}R{\mathrm{FeO}}_3\right)$, may amplify the weak ferromagnetic moment on Fe, making these materials more appealing as multiferroics. To elucidate the interaction strength between the rare-earth and Fe ions as well as the magnetic moment of the rare-earth ions, element-specific magnetic characterization is needed. Using x-ray magnetic circular dichroism, we have studied the ferrimagnetism in $h\text{−}{\mathrm{YbFeO}}_3$ by measuring the magnetization of Fe and Yb separately. The results directly show antialignment of magnetization of Yb and Fe ions in $h\text{−}{\mathrm{YbFeO}}_3$ at low temperature, with an exchange field on Yb of about 17 kOe. The magnetic moment of Yb is about $1.6{\mu }_B$ at low temperature, significantly reduced compared with the $4.5{\mu }_B$ moment of a free ${\mathrm{Yb}}^{3+}$. In addition, the saturation magnetization of Fe in $h\text{−}{\mathrm{YbFeO}}_3$ has a sizable enhancement compared with that in $h\text{−}{\mathrm{LuFeO}}_3$. These findings directly demonstrate that ferrimagnetic order exists in $h\text{−}{\mathrm{YbFeO}}_3$; they also account for the enhancement of magnetization and the reduction of coercivity in $h\text{−}{\mathrm{YbFeO}}_3$ compared with those in $h\text{−}{\mathrm{LuFeO}}_3$ at low temperature, suggesting an important role for the rare-earth ions in tuning the multiferroic properties of $h\text{−}R{\mathrm{FeO}}_3$.

• Received 22 March 2017
• Revised 21 May 2017

DOI:https://doi.org/10.1103/PhysRevB.95.224428