摘要
We report a study of the structure and magnetic properties of the S=3/2 zigzag spin chain compound BaCoTe_(2)O_(7).Neutron diffraction measurements show that it crystallizes in the noncentrosymmetric space group Ama2 with a canted↑↑↓↓spin structure along the quasi-one-dimensional zigzag chain and a moment size of 1.89(2)μBat 2 K.Both magnetic susceptibility and specific heat measurements yield an antiferromagnetic phase transition at TN=6.2 K.A negative Curie-Weiss temperature,ΘCW=-74.7(2) K,and an empirical frustration parameter,f=|ΘCW|/TN≈12,are obtained by fitting the magnetic susceptibility,indicating antiferromagnetic interactions and strong magnetic frustration.From 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 in the polarization via the exchange-striction mechanism.
基金
supported by the National Natural Science Foundation of China(Grant No.11904414)
the National Key Research and Development Program of China(Grant No.2019YFA0705702)
supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0306001,and 2017YFA0206203)
the National Natural Science Foundation of China(Grant No.11974432)
the Guangdong Basic and Applied Basic Research Fund(Grant No.2019A1515011337)
the Leading Talent Program of Guangdong Special Projects。
