Single crystal growth and electrical transport of two-dimensional van der Waals antiferromagnetic Fe1.3Te

Abstract

Two-dimensional (2D) van der Waals (vdW) materials with promising electrical, magnetic, optical, and mechanical properties have shown great potential for next-generation electronics and spintronics. Among them, vdW Fe_1+xTe with varying Fe contents exhibits exotic quantum phenomena such as magnetism and superconductivity. However, they are still underexplored for Fe_1+xTe with sufficiently-high Fe contents, and the electrical transport properties of Fe_1+xTe crystals with higher Fe contents are still unknown. Here, we grow a vdW antiferromagnetic crystal Fe_1.3Te with a Néel temperature of ∼66 K by a Sn/Te-flux method. The as-grown Fe_1.3Te has the highest Fe content (x = 0.3) compared to known Fe_1+xTe systems, and shows a typical structural phase transition at ∼49 K. As the temperature increases, a transition from electron-dominated to hole-dominated charge carriers is observed in exfoliated Fe_1.3Te nanosheets, with a decrease in transition temperature from ∼44 to ∼38 K by reducing the thickness from 323 to 19 nm. These findings provide opportunities for the study of Fe-based vdW magnets and their potential applications.