The Electronic and Magnetic Properties of Hexagonal and Oblique Carbon Foam Surfaces

The recent observation of 2D magnetism in 3D graphene has generated considerable interest. Herein, three types of carbon foam (CF) models are proposed composed of hybridized carbon atoms ( and ), namely hexagonal A, oblique B, and oblique C. Each CF model can exhibit different surface shapes, showcasing either or terminations, with or without hydrogen saturation. The first‐principles calculations confirm that only the A model exhibits 2D surface magnetism. The A model with bare dangling carbon bond (A‐B) exhibits an antiferromagnetic ground state, while the ‐terminated A model under full H saturation or with bare dangling bonds on the surfaces (A‐S or A‐B) shows a ferromagnetic ground state. In addition, the electronic properties of A, B, and C structures are investigated. The research findings indicate that by modifying the model structure and terminal surfaces, it is possible to achieve a transition from metal to semiconductor. This unique surface magnetism of CFs represents a significant advancement in the field of 2D magnetism.