High-throughput screening of two-dimensional ferromagnetic materials with high Curie temperatures

Two-dimensional (2D) ferromagnetic (FM) materials have garnered significant interest for their unique magnetic and electronic properties, with promising applications in spintronics and quantum computing. In this work, we performed high-throughput computational screening on the C2DB and 2DMatPedia databases and identified 34 potential 2D FM materials with Curie temperatures (T_c) above liquid nitrogen temperature (77 K). Among them, 8 systems exhibit T_c near or even exceeding 300 K. In particular, Sr₃Mn₂Cl₂O₅ (395 K), Al₂CoSe₄ (335 K), and CrAuP₂S₆ (295 K) emerge as previously unreported high-T_c candidates. Through elemental substitution in Sr₃Mn₂Cl₂O₅, we further designed a thermodynamically stable compound, Ba₃Mn₂I₂O₅, which exhibits an enhanced T_c of 669 K. We further constructed bilayer heterostructures from selected candidates and uncovered interlayer-interaction-driven altermagnetism and sliding ferroelectricity.