Electronic structure and direct observation of ferrimagnetism in multiferroic hexagonal YbFeO3

• Published in: arXiv.org 2017-06
• Main Authors: Cao, Shi, Sinha, Kishan, Zhang, Xin, Zhang, Xiaozhe, Wang, Xiao, Yin, Yuewei, N'Diaye, Alpha T, Wang, Jian, Keavney, David J, Paudel, Tula R, Liu, Yaohua, Cheng, Xuemei, Tsymbal, Evgeny Y, Dowben, Peter A, Xu, Xiaoshan
• Format: Article
• Language: English
• Subjects: Coercivity; Dichroism; Electronic structure; Ferrimagnetism; Ferromagnetic materials; Magnetic fields; Magnetic moments; Magnetic properties; Magnetic saturation; Magnetism; Magnetization; Metal ions; Multiferroic materials; Rare earth elements
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1703.08482

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.