A single-crystal neutron diffraction study on magnetic structure of the   quasi-one-dimensional antiferromagnet SrCo2V2O8
  The magnetic structure of the spin-chain antiferromagnet SrCo2V2O8 is determined by single-crystal neutron diffraction experiment. The system undergoes magnetic long range order below T_N = 4.96 K. The moment of 2.16{\mu}_B per Co at 1.6 K in the screw chain running along the c axis alternates in the c-axis. The moments of neighboring screw chains are arranged antiferromagnetically along one in-plane axis and ferromagnetically along the other in-plane axis. This magnetic configuration breaks the 4-fold symmetry of the tetragonal crystal structure and leads to two equally populated magnetic twins with antiferromagnetic vector in the a or b axis. The very similar magnetic state to the isostructural BaCo2V2O8 warrants SrCo2V2O8 another interesting half-integer spin-chain antiferromagnet for investigation on quantum antiferromagnetism. 
Juanjuan Liu, Jinchen Wang, Wei Luo, Jieming Sheng, Zhangzhen He, S.A.   Danilkin, Wei Bao
cond-mat.str-el