Exploration of novel foam structures of carbon, boron nitride, and boron carbon nitride: Stability and electronic properties

This study explores, through first-principles calculations, the structural stability, electronic properties, and potential applications of nanofoam structures consisting of graphenelike nanoribbons of C, B, and N atoms with edges covalently connected by triple junctions. Among the stoichiometries considered, pristine BN structures are the most stable, with formation energies per atom 26% smaller than those of the corresponding pristine carbon foams, on average. Remarkably, one of the BN foam structures was found to be more stable than the planar hexagonal boron nitride (h-BN) structure. The least stable foam structures are those with B, C, and N atoms, as expected due to the existence of ``wrong'' C-B and C-N bonds. Interestingly, these B-C-N foams are more stable in all structures considered when carbon atoms are located at the triple junction regions. A variety of electronic properties are found among the foams investigated. Interestingly, one of the boron nitride foams is both ferromagnetic and metallic. These findings provide valuable insights into the design and optimization of lightweight nanoporous materials for use in aerospace, energy storage, and electronics devices.