Two-dimensional (2D) magnetic materials have attracted tremendous attention in the spintronics and nanoelectronics fields. However, intrinsic and robust 2D magnetism is hard to achieve. Using high-throughput first-principles calculations, herein we have explored 2D ternary compounds of a transition metal $(\mathrm{X}=\mathrm{Fe}, \mathrm{Mn}, \mathrm{Cr})$, Ge, and Te, with diverse stoichiometries and geometric configurations. We screened 34 ferromagnetic and 111 antiferromagnetic XGT monolayer structures, including metals, half-metals, and semiconductors, with high magnetic transition temperatures for practical uses. The coupling strength of ferromagnetism in XGT monolayers is related to the ratio of the transition metal element, while the band gap opening is affected by the occupancy of transition metal $d$ states and the Te content. Therefore, the electronic and magnetic structures of XGT monolayers can be manipulated by their stoichiometries. This work delivers a unique perspective for designing compound functional materials and enriches the family of 2D magnets for technological applications.

• Received 7 December 2021
• Revised 14 March 2022
• Accepted 28 March 2022

DOI:https://doi.org/10.1103/PhysRevMaterials.6.044005