The synthesis and magnetic properties of BaFe₂Se₃ single crystals

The iron selenide compound BaFe₂Se₃ was synthesized by a two-step high-temperature solid state method. The single-crystal X-ray determination of the prepared compound revealed a three-dimensional structure consisting of double chains of edge-sharing FeSe₄ tetrahedra separated by Ba²⁺. In contrast to the case for alkali metal intercalated iron-based chalcogenides (like KₓFe₂₋ySe₂), the double chains of BaFe₂Se₃ were cut out of the two-dimension layers. X-ray photoelectron spectroscopy measurements indicated that there existed two valence states of iron: Fe²⁺ and Fe³⁺, which proved there were vacancies in the iron sites. In addition, the magnetic measurements demonstrated that BaFe₂Se₃ was antiferromagnetic and the Neel temperature of the sample was related to the average electronic spin of iron sites.