Monolayer and bilayer lanthanide compound Gd₂C with large magnetic anisotropy energy and high Curie temperature

Comparing with transition metal compounds, lanthanide compounds hold promising potential as spintronic materials to generate large magnetic moments and strong magnetic anisotropic. By conducting in-depth theoretical calculations, we explored the electronic and magnetic properties of monolayer and bilayer Gd₂C, the f-electron lanthanide compound. Monolayer Gd₂C is a ferromagnetic (FM) half-metal with large band gap (1.68 eV) in the semiconducting spin-channel. It has large magnetic anisotropic energy (MAE) (703 μeV/Gd atom), and Curie temperature (T_C) of 322 K, above room temperature and higher compared with Gd metal and layered Gd₂C. Under 5% biaxial strain, its T_C increases to 392 K. The robust half-metallicity of monolayer Gd₂C is highly desirable for spin current generation and injection. In addition, we found that bilayer Gd₂C maintains to be FM at all stacking orders. Two stable stacking configurations of bilayer Gd₂C were identified; both are FM metals and may co-exist at room temperature. Our results demonstrate potential applications of 2D lanthanide compound Gd₂C in the field of spintronics.