Large Polarization Switching and High-Temperature Magnetoelectric Coupling in Multiferroic GaFeO3 Systems

Hui Wang; Yang Zhang; Koki Tachiyama; Zhaoyang Xia; Jinghong Fang; Qin Li; Guofeng Cheng; Yun Shi; Jianding Yu; Tsukasa Katayama; Shintaro Yasui; Mitsuru Itoh

doi:10.1021/acs.inorgchem.0c02855

Large Polarization Switching and High-Temperature Magnetoelectric Coupling in Multiferroic GaFeO₃ Systems

Inorg Chem. 2021 Jan 4;60(1):225-230. doi: 10.1021/acs.inorgchem.0c02855. Epub 2020 Dec 15.

Authors

Hui Wang¹, Yang Zhang¹, Koki Tachiyama², Zhaoyang Xia^{1

3}, Jinghong Fang^{1

3}, Qin Li¹, Guofeng Cheng¹, Yun Shi¹, Jianding Yu^{1

3}, Tsukasa Katayama⁴, Shintaro Yasui^{2

5}, Mitsuru Itoh^{2

6}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China.
² Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Department of Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
⁵ Laboratory for Advanced Nuclear Energy, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
⁶ Research Institute for Advanced Electronics and Photonics (RIAEP), National Institute of Advanced Industrial Science and Technology Central-2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.

PMID: 33320663
DOI: 10.1021/acs.inorgchem.0c02855

Abstract

GaFeO₃-type iron oxides are promising multiferroics due to the coexistence of large spontaneous magnetization and polarization near room temperature. However, the high leakage current and difficulties associated with synthesizing single crystals make it difficult to achieve two important features in the system: a large ferroelectric polarization switching and magnetoelectric coupling at a high-temperature region. Herein, we report successful achievement of these features by preparing high-quality Sc-doped GaFeO₃ single crystals (Sc_xGa_1-x/2Fe_1-x/2O₃ with x = 0-0.3) using the floating zone method. The x ≥ 0.05 crystals exhibit a leakage current 10⁴ times lower than the x = 0 crystals, highlighting the importance of Sc doping. Because of the reduced leakage current, the Sc-doped crystals exhibit large ferroelectric polarization switching along the c-axis with a remanent polarization of 22-25 μC/cm², which is close to the theoretically predicted polarization value of 25-28 μC/cm². In addition, the Sc-doped crystals exhibit ferrimagnetism with magnetic anisotropy along the a-axis. Furthermore, a magnetic-field-induced modulation of polarization is observed in the x = 0.15 crystal even at a relatively high temperature, i.e., 100 K.