An antisite defect mechanism for room temperature ferroelectricity in orthoferrites

Author:Date:2021-10-28Views:26

论文题目:An antisite defect mechanism for room temperature ferroelectricity in orthoferrites

论文作者:Shuai Ning*, Abinash Kumar, Konstantin Klyukin, Eunsoo Cho, Jong Heon Kim, Tingyu Su, Hyun-Suk Kim, James M. LeBeau, Bilge Yildiz, Caroline A. Ros

发表期刊:Nature Communications, 12(1), 4298, 2021    

Abstract: 

Single-phase multiferroic materials that allow the coexistence of  ferroelectric and magnetic ordering above room temperature are highly  desirable, motivating an ongoing search for mechanisms for  unconventional ferroelectricity in magnetic oxides. Here, we report an  antisite defect mechanism for room temperature ferroelectricity in  epitaxial thin films of yttrium orthoferrite, YFeO3, a  perovskite-structured canted antiferromagnet. A combination of  piezoresponse force microscopy, atomically resolved elemental mapping  with aberration corrected scanning transmission electron microscopy and  density functional theory calculations reveals that the presence of Y-Fe  antisite defects facilitates a non-centrosymmetric distortion promoting  ferroelectricity. This mechanism is predicted to work analogously for  other rare earth orthoferrites, with a dependence of the polarization on  the radius of the rare earth cation. Our work uncovers the distinctive  role of antisite defects in providing a mechanism for ferroelectricity  in a range of magnetic orthoferrites and further augments the  functionality of this family of complex oxides for multiferroic  applications. Ferroelectricity in orthoferrite perovskites has  stimulated intense research, but the mechanism remains unclear. Here,  the authors propose an antisite defect mechanism for introducing  ferroelectricity in magnetically ordered YFeO3 and the family of rare  earth orthoferrites.