时间空间反演对称同时破缺模型材料的发现

（A Ferrotoroidic Candidate with Well-Separated Spin Chains ）

J. Zhang, X. C. Wang, L. Zhou, G. X. Liu, D. T. Adroja, I. Da Silva, F. Demmel, D. Khalyavin, J. Sannigrahi, H. S. Nair, L. Duan, J. F. Zhao, Z. Deng, R. Z. Yu, X. Shen, R. C. Yu, H. Zhao, J. M. Zhao, Y. W. Long, Z. W. Hu, H. J. Lin, T. S. Chan, C. T. Chen, W. Wu, C. Q. Jin

Adv. Mater. 34, 2106728 (2022)

Highlights: 中科院（CAS）, 中科院物理所（IOP）, 中国材料研究学会，材料科学与工程

The search of novel quasi one-dimensional (1D) materials is one of the important aspects in the field of material science. Toroidal moment, the order parameter of ferrotoroidic order, can be generated by a head-to-tail configuration of magnetic moment. It has been theoretically proposed that one-dimensional (1D) dimerized and antiferromagnetic-like spin chain hosts ferrotoroidicity and has the toroidal moment composed of only two antiparallel spins. Here, we report a ferrotoroidic candidate of Ba6Cr2S10 with such a theoretical model of spin chain. The structure consists of unique dimerized face-sharing CrS6 octahedral chains along the c axis. An antiferromagnetic-like ordering at ~10 K breaks both space- and time-reversal symmetries and the magnetic point group of mm'2' allows three ferroic orders in Ba6Cr2S10: (anti)ferromagnetic, ferroelectric and ferrotoroidic orders. Our investigation reveals that Ba6Cr2S10 is a rare ferrotoroidic candidate with quasi 1D spin chain, which can be considered as a starting point for the further exploration of the physics and applications of ferrotoroidicity.