Stability and electronic structure of potassium-intercalated hexagonal boron nitride from density functional calculations

By using the local-density approximation in density functional theory, we explore the possibility of a metallic layered compound derived from hexagonal boron nitride (h-BN). We find that the intercalation process of potassium atoms into the interlayer spacing of h-BN is exothermic with a formation energy of approximately 1.6 eV per potassium atom, and that the electronic structure of potassium-intercalated h-BN under equilibrium interlayer distance is metallic, in which electrons are injected into unoccupied, nearly-free-electron states. The calculated Fermi surfaces of the compound exhibit characteristics similar to that of graphite intercalation compounds doped with alkali/alkali-earth metals.