The spin-induced ferroelectricity in quasi-1D spin chain system is little known, which could be fundamentally different from those in three-dimensional (3D) system. Here, we report the ferroelectricity driven by a tilted screw spin order and its exotic dynamic in the spin-chain compound Ba9Fe3Se15. It is found that the spin-induced polarization has already occurred and exhibits magnetoelectric coupling behavior far above the long-range spin order (LRSO) at TN = 14 K. The polarized entities grow and their dynamic responses slow down gradually with decreasing temperature and permeate the whole lattice to form 3D ferroelectricity at TN. Our results reveal that the short-range spin orders (SRSOs) in the decoupled chains play a key role for the exotic dynamic in this dimension reduced system. Ba9Fe3Se15 is the only example so far which exhibits electric polarization above LRSO temperature because of the formation of SRSOs.
@article{arxiv.2207.10834,
title = {Ferroelectricity driven by magnetism in quasi-one-dimensional Ba9Fe3Se15},
author = {Jun Zhang and Xiancheng Wang and Yiqing Hao and Guangxiu Liu and Long Zhou and Daniel M. Pajerowski and Jian-Tao Wang and Jinlong Zhu and Jun Zhao and Jiulong Wang and Yifeng Zhao and Chungang Duan and Youwen Long and Chang-Jong Kang and Martha Greenblatt and Changqing Jin},
journal= {arXiv preprint arXiv:2207.10834},
year = {2022}
}