Electronic structure and direct observation of ferrimagnetism in multiferroic hexagonal YbFeO3

Authors

Shi Cao, University of Nebraska - Lincoln
Kishan Sinha, University of Nebraska - Lincoln
Xin Zhang, University of Nebraska - LincolnFollow
Xiaozhe Zhang, University of Nebraska - Lincoln
Xiao Wang, Bryn Mawr College
Yuewei Yin, University of Nebraska - Lincoln
Alpha T. N’Diaye, Lawrence Berkeley National Lab
Jian Wang, Canadian Light Source
David J. Keavney, Argonne National Lab
Tula R. Paudel, University of Nebraska-LincolnFollow
Yaohua Liu, Oak Ridge National Lab
Xuemei Cheng, Bryn Mawr College
Evgeny Y. Tsymbal, University of Nebraska - LincolnFollow
Peter A. Dowben, University of Nebraska - LincolnFollow
Xiaoshan Xu, University of Nebraska-LincolnFollow

Date of this Version

6-26-2017

Citation

PHYSICAL REVIEW B 95, 224428 (2017).

DOI: 10.1103/PhysRevB.95.224428

Comments

Copyright 2017 American Physical Society. Used by permission.

Abstract

The magnetic interactions between rare-earth and Fe ions in hexagonal rare-earth ferrites (h-RFeO₃), 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 antialignment 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 1.6μB at low temperature, significantly reduced compared with the 4.5 μ_B 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-RFeO₃.