TY - JOUR AU - Guo, H. AU - Zhao, L. AU - Schmidt, W. AU - Fernández-Díaz, M. T. AU - Becker, Ch. AU - Melendez-Sans, A. AU - Peng, W. AU - Zbiri, M. AU - Hansmann, P. AU - Komarek, A. C. TI - Multiferroic properties of melanothallite Cu 2 OCl 2 JO - Physical review materials VL - 3 IS - 12 SN - 2475-9953 CY - College Park, MD PB - APS M1 - FZJ-2020-00050 SP - 124405 PY - 2019 AB - Here we report on P−E hysteresis loop measurements that unravel the ferroelectric nature of melanothallite Cu2OCl2, a new multiferroic material with high critical temperature. Its spin structure was investigated by polarized and unpolarized neutron scattering experiments which reveal a cycloidal magnetic structure with vector chirality (magnetic polarity) that can be inverted by opposite poling of the sample with an inverted electric field. This shows that Cu2OCl2 is a spin-induced ferroelectric material. Finally, we show that the ferroelectric properties of Cu2OCl2 are driven by the inverse Dzyaloshinskii-Moriya interaction mechanism which is also able to predict the observed direction of the ferroelectric polarization properly. The origin of the noncollinear spin structure in melanothallite are competing AFM-FM exchange couplings which we estimate from a combined ab initio + cluster configuration interaction calculation. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000502803200003 DO - DOI:10.1103/PhysRevMaterials.3.124405 UR - https://juser.fz-juelich.de/record/872530 ER -