Iron telluride ladder compounds: Predicting the structural and magnetic properties of BaFe2Te3

Abstract

Since the discovery of pressure-induced superconductivity in the two-leg ladder system BaFe2X3 (X=S, Se), with the 3d iron electronic density n=6, quasi-one-dimensional iron-based ladders have attracted considerable attention. Here, we use density-functional theory to predict that the novel n=6 iron ladder BaFe2Te3 could be stable with a similar crystal structure as BaFe2Se3. Our results also indicate that BaFe2Te3 will display a complex 2×2 block-type magnetic order. Due to the magnetic striction effects of this block order, BaFe2Te3 should be a magnetic noncollinear ferrielectric system with a net polarization 0.31μC/cm2. In general, the similar electronic density and magnetic ground state of Te- and Se-based ladders indicates both should display similar properties. In particular, the physical and structural similarity with BaFe2Se3 suggests that BaFe2Te3 could become superconducting under high pressure.