Iron telluride ladder compounds: Predicting the structural and magnetic properties of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>BaFe</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>
Yang Zhang, Ling-Fang Lin, Adriana Moreo, Shuai Dong, Elbio Dagotto
Abstract
Since the discovery of pressure-induced superconductivity in the two-leg ladder system ${\mathrm{BaFe}}_{2}{X}_{3}$ ($X=\mathrm{S}$, 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 ${\mathrm{BaFe}}_{2}{\mathrm{Te}}_{3}$ could be stable with a similar crystal structure as ${\mathrm{BaFe}}_{2}{\mathrm{Se}}_{3}$. Our results also indicate that ${\mathrm{BaFe}}_{2}{\mathrm{Te}}_{3}$ will display a complex $2\ifmmode\times\else\texttimes\fi{}2$ block-type magnetic order. Due to the magnetic striction effects of this block order, ${\mathrm{BaFe}}_{2}{\mathrm{Te}}_{3}$ should be a magnetic noncollinear ferrielectric system with a net polarization $0.31\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{C}/{\mathrm{cm}}^{2}$. 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 ${\mathrm{BaFe}}_{2}{\mathrm{Se}}_{3}$ suggests that ${\mathrm{BaFe}}_{2}{\mathrm{Te}}_{3}$ could become superconducting under high pressure.