Magnetic susceptibility, specific heat, and neutron powder diffraction measurements have been performed on polycrystalline Li2Co(WO4)2 samples. Under zero magnetic field, two successive magnetic transitions at TN1 ~ 9.4 K and TN2 ~ 7.4 K are observed. The magnetic ordering temperatures gradually decrease as the magnetic field increases. Neutron diffraction reveals that Li2Co(WO4)2 enters an incommensurate magnetic state with a temperature dependent k between TN1 and TN2. The magnetic propagation vector locks-in to a commensurate value k = (1/2, 1/4, 1/4) below TN2. The antiferromagnetic structure is refined at 1.7 K with Co2+ magnetic moment 2.8(1) uB, consistent with our first-principles calculations.
@article{arxiv.2111.04944,
title = {Incommensurate-commensurate magnetic phase transition in the double tungstate Li2Co(WO4)2},
author = {Xiyu Chen and Ning Ding and Meifeng Liu and Tao Zou and V. Ovidiu Garlea and Jingwen Gong and Fei Liu and Yunlong Xie and Lun Yang and Shuhan Zheng and Xiuzhang Wang and Shuai Dong and T. Charlton and Jun-Ming Liu},
journal= {arXiv preprint arXiv:2111.04944},
year = {2022}
}