Electronic structure and direct observation of ferrimagnetism in multiferroic hexagonal YbFeO3

TL;DR

This study uses element-specific magnetic measurements to reveal ferrimagnetism in h-YbFeO3, showing anti-aligned Yb and Fe moments, and highlights the role of rare-earth ions in tuning multiferroic properties.

Contribution

It provides direct experimental evidence of ferrimagnetic order in h-YbFeO3 and details the magnetic interactions between Yb and Fe ions.

Findings

Yb and Fe magnetizations are anti-aligned at low temperature

Yb magnetic moment is about 1.6 μB, reduced from free Yb3+

Saturation magnetization of Fe is enhanced compared to h-LuFeO3

Abstract

The magnetic interaction between rare-earth and Fe ions in hexagonal rare-earth ferrites (h-REFeO3), 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-YbFeO3 by measuring the magnetization of Fe and Yb separately. The results directly show anti-alignment of magnetization of Yb and Fe ions in h-YbFeO3 at low temperature, with an exchange field on Yb of about 17 kOe. The magnetic moment of Yb is about 1.6 \muB at low-temperature, significantly reduced compared with the 4.5 \muB moment of a free Yb3+. In addition, the saturation magnetization of Fe in h-YbFeO3 has a sizable enhancement compared with that in h-LuFeO3. These findings directly demonstrate that ferrimagnetic order exists in h-YbFeO3; they also account for the enhancement of magnetization and the reduction of coercivity in h-YbFeO3 compared with those in h-LuFeO3 at low temperature, suggesting an important role for the rare-earth ions in tuning the multiferroic properties of h-REFeO3.