Ferromagnetism below 10 K in Mn doped BiTe

TL;DR

This study reports ferromagnetism below 10 K in Mn-doped BiTe, highlighting how anti-site defects enhance Mn solubility and induce ferromagnetic behavior, with experimental evidence from magnetic hysteresis and Hall effect measurements.

Contribution

It demonstrates that TeBi anti-site defects significantly increase Mn solubility and induce ferromagnetism in BiTe-based materials, providing new insights into defect-controlled magnetic properties.

Findings

Ferromagnetism observed below 10 K in Mn-doped BiTe.

TeBi anti-site defects enhance Mn solubility.

Magnetic hysteresis and anomalous Hall Effect confirmed ferromagnetic behavior.

Abstract

Ferromagnetism is observed below 10 K in [Bi0.75Te0.125Mn0.125]Te. This material has the BiTe structure, which is made from the stacking of two Te-Bi-Te-Bi-Te blocks and one Bi-Bi block per unit cell. Crystal structure analysis shows that Mn is localized in the Bi2 blocks, and is accompanied by an equal amount of TeBi anti-site occupancy in the Bi2Te3 blocks. These TeBi anti-site defects greatly enhance the Mn solubility. This is demonstrated by comparison of the [Bi1-xMnx]Te and [Bi1-2xTexMnx]Te series; in the former, the solubility is limited to x = 0.067, while the latter has xmax = 0.125. The magnetism in [Bi1-xMnx]Te changes little with x, while that for [Bi1-2xTexMnx]Te shows a clear variation, leading to ferromagnetism for x > 0.067. Magnetic hysteresis and the anomalous Hall Effect are observed for the ferromagnetic samples.