Anisotropy in BaFe$_{2}$Se$_{3}$ single crystals with double chains of FeSe tetrahedra

Since two-dimensional (2D) FePn or FeCh (Pn = pnictogens, Ch = chalcogens) tetrahedron layers are the common structural ingredient in all iron based superconductors, they are probably related to high temperature superconductivity. In order to fully understand the nature of iron-based superconductivity, study of materials containing similar FePn or FeCh tetrahedron as building blocks is of significant interest. BaFe$_{2}$Se$_{3}$ contains one-dimensional (1D) double chains of edge shared Fe-Se tetrahedra along the b-axis, in contrast to iron chalcogenide superconductors which feature two-dimensional (2D) Fe-Se planes. We report the anisotropic physical properties and local crystal structure of Ba$_{1.00(4)}$Fe$_{1.9(1)}$Se$_{3.1(1)}$ single crystals. It shows that BaFe$_{2}$Se$_{3}$ is a semiconductor with a short-range AFM correlation at the room temperature and a long-range AFM order below 255 K. Composition analysis indicates that all crystallographic sites are fully occupied. X-ray absorption near edge structure (XANES) result shows that the valence of Fe is about 1.87+.