Structure and magnetic properties of the S = 3/2 zigzag spin chain antiferromagnet BaCoTe2O7

• DOI: 10.1007/s11433-021-1726-0
• Publication Date: 2021-07-05T23:04:36Z
• Authors: Lisi Li; Xunwu Hu; Zengjia Liu; Jia Yu; Benyuan Cheng; Sihao Deng; Lunhua He; Kun Cao; Dao-Xin Yao; Meng Wang
• Keywords: Zigzag; Magnetic structure

We report an investigation on structure and magnetic properties of the $S=3/2$ zigzag spin chain compound BaCoTe$_2$O$_7$. Neutron diffraction measurements reveal BaCoTe$_2$O$_7$ crystallizes in the noncentrosymmetric space group $Ama2$ with a canted $\uparrow\uparrow\downarrow\downarrow$ spin structure along the quasi-one-dimensional zigzag chain and a moment size of $1.89(2)��_B$ at 2 K. Magnetic susceptibility and specific heat measurements yield an antiferromagnetic phase transition at $T_N=6.2$ K. A negative Curie-Weiss temperature $��_{CW}=-74.7(2)$ K and an empirical frustration parameter of $f=|��_\text{CW}|/T_\text{N}\approx12$ is obtained from fitting the magnetic susceptibility, indicating antiferromagnetic interactions and strong magnetic frustration. By employing ultraviolet-visible absorption spectroscopy and first principles calculations, an indirect band gap of 2.68(2) eV is determined. We propose that the canted zigzag spin chain of BaCoTe$_2$O$_7$ may produce a change of the polarization via exchange striction mechanism.<br/>11 pages, 5 Figures, Supplemental material<br/>