Room-temperature multiferroic properties in NiBi₂O₄

Kai Chen^1,2,3, Feng Gao^1,2, Weiwei Lin^1,2, Hongling Cai^1,2, Guolin Li^1,2, Xingwei Dong^1,2, Song Peng^1,2, Xiaoshan Wu^1,2, Mao Yang^1,2, Jun Du^1,2, Xiaomei Lu^1,2, Junming Liu^1,2 and Jinsong Zhu^1,2

¹  National Laboratory of Solid State Microstructures, Nanjing University - Nanjing 210093, PRC
²  Department of Physics, Nanjing University - Nanjing 210093, PRC
³  Department of Physics, Nanjing University of Science and Technology - Nanjing 210094, PRC

Corresponding authors: pacinonono@yahoo.com.cn - jszhu@nju.edu.cn

Received: 6 August 2009
Accepted: 21 December 2009

Abstract

Magnetism and ferroelectricity at room temperature are observed in the NiBi₂O₄ ceramics. Both the time reversal and the inversion symmetry of the structure (space group F-43m) are broken. The saturation magnetization is 0.028 emu/g and the saturation polarization 2P_s ~ 4.0 μC/cm². NiBi₂O₄ also shows other room-temperature multiferroic properties, e.g. the piezoelectric coefficient (d₃₃), the polarized dielectric character, the magneto-dielectric response and the magnetoelectric effect.