Iron telluride ladder compounds: Predicting the structural and magnetic properties of BaFe$_2$Te$_3$

TL;DR

This study uses DFT calculations to predict that BaFe$_2$Te$_3$, a novel iron telluride ladder compound, is structurally stable, exhibits complex magnetic order, and may become superconducting under high pressure.

Contribution

The paper predicts the stability, magnetic properties, and potential superconductivity of BaFe$_2$Te$_3$, a new iron telluride ladder compound, using first-principles calculations.

Findings

BaFe$_2$Te$_3$ is predicted to be structurally stable.

It exhibits a 2×2 Block-type magnetic order.

Potential for superconductivity under high pressure.

Abstract

Since the discovery of pressure-induced superconductivity in the two-leg ladder system BaFe$_2X_3$ ($X$=S, Se), with the 3$d$ iron electronic density $n = 6$, the quasi-one-dimensional iron-based ladders have attracted considerable attention. Here, we use Density Functional Theory (DFT) to predict that the novel $n = 6$ iron ladder BaFe$_2$Te$_3$ could be stable with a similar crystal structure as BaFe$_2$Se$_3$. Our results also indicate that BaFe$_2$Te$_3$ will display the complex 2$\times$2 Block-type magnetic order. Due to the magnetic striction effects of this Block order, BaFe$_2$Te$_3$ should be a magnetic noncollinear ferrielectric system with a net polarization $0.31$ $\mu$C/cm$^2$. Compared with the S- or Se-based iron ladders, the electrons of the Te-based ladders are more localized, implying that the degree of electronic correlation is enhanced for the Te case which may induce additional interesting properties. The physical and structural similarity with BaFe$_2$Se$_3$ also suggests that BaFe$_2$Te$_3$ could become superconducting under high pressure.