Tailored Magnetic Properties of Quasi-2D Cr-Se-Te Materials via Selective Se Substitution

Two-dimensional (2D) magnetic materials hold immense potential for high-density data storage and transfer applications. Recent studies on Cr₂Te₃ have revealed its quasi-2D nature and exceptional magnetic properties, making it an attractive material for various applications. However, to broaden its application scope, it is essential to effectively control its magnetism. In this study, we demonstrate that the substitution of tellurium (Te) atoms with selenium (Se) atoms offers a promising approach to engineer the magnetic properties of Cr₂Te₃. Our findings show enhanced hard magnetism in Cr₂(Se_xTe_1-x)₃ at low Se substitution and a transition from ferromagnetic to antiferromagnetic at high substitution. Importantly, at a Se substitution concentration of 0.13, the coercive field shows a remarkable increase, nearly 60 times greater than that of Cr₂Te₃, while maintaining a high saturation magnetization. The coexistence of large M_S and H_C is superior to that of most bulk ferromagnetic materials. Theoretical analysis and DFT calculation reveals that the significant hard magnetism arises from the enhanced domain wall energy, and the antiferromagnetic transition is caused by the evolving magnetic configuration determined by the varied magnetic interactions. This study presents a highly tunable method for fine-tuning of the magnetic properties of quasi-2D materials, consequently opening up new possibilities for spintronics applications.