Significant enhancement in the magnetic properties of Cr2Te3 nanosheets by atom substitution doping

Abstract

Ferromagnetic Cr₂Te₃ nanocrystals, with their high spin–orbit coupling and low symmetry, have attracted considerable attention as rare-earth-free magnetic nanomaterials due to their potential to achieve high magnetic anisotropy. However, their relatively low values of remanence (M_r) and saturation (M_S) magnetisation limit their energy product, making them unsuitable for practical applications. Herein, we report a straightforward one-pot heat-injection technique for the synthesis of high-remanence hexagonal Cr₂Te₃ nanosheets by heterogeneous doping with atoms of M (M = V, Mn and Se). The doped materials provide enhanced M_r and M_S at an unchanged Curie temperature (T_C), resulting in excellent hard magnetic properties. With Mn doping, the Mr of the matrix increases significantly, reaching 18.38 emu g⁻¹ at 5 K, far exceeding the original undoped Cr₂Te₃ nanosheets. The nearly square hysteresis loop makes it valuable for many low temperature applications. These results provide a valuable case for tuning the magnetism of ferromagnetic Cr₂Te₃ by substitutional doping.