Magnetic‐Field Controllable Displacement‐Type Ferroelectricity Driven by Off‐Center Fe<sup>2+</sup> Ions in CaFe<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub> Perovskite
Dabiao Lu, Denis Sheptyakov, Yingying Cao, Haoting Zhao, Jie Zhang, Maocai Pi, Xubin Ye, Zhehong Liu, Xueqiang Zhang, Zhao Pan, Xingxing Jiang, Zhiwei Hu, Yi‐feng Yang, Pu Yu, Youwen Long
Abstract
Abstract Displacement‐type ferroelectrics usually exclude magnetic d ‐electron contribution. Applying a magnetic field thus can little change the electric polarization. Herein, a magnetic ionic driven displacement‐type perovskite ferroelectric CaFe 3 Ti 4 O 12 is reported. In this compound, magnetic Fe 2+ ions contribute to both ferroelectric and antiferromagnetic orders respectively at T C ≈107 and T N ≈ 3.1 K, resulting in coupled electric and magnetic domains. A moderate magnetic field can induce a metamagnetic transition toward ferromagnetic correlations. External magnetic fields can thus readily tune the magnetic and the joint ferroelectric domains, giving rise to exceptional magnetic‐field controllable displacement‐type polarization with a large magnetoelectric (ME) coupling coefficient. This study opens up a new avenue to find unprecedented ME effects in displacement‐type ferroelectrics for numerous applications.