Staging Phenomena in Lithium-Intercalated Boron-Carbon.

Hole-doped LiBC has become of great interest as a candidate for high-temperature superconductivity with its structural similarity to MgB and as a possible cathode for rechargeable lithium batteries with the large graphenelike BC hexagons. The limitation on synthesis studies has detracted from the structural and electronic properties and application studies of Li BC. Here, we present the successful synthesis of hole-doped LiBC and its structural and electronic characterization using detailed structural modeling based on a unique stage-2 Daumas-Hérold-type domain structure consistent with X-ray diffraction data. The strong intralayer motion of the guest Li island induces extraordinary structural properties, such as staging and staging disorder, which are confirmed by the compressibility results obtained from LiBC (anisotropic cell compressibility with B ∼ 134 GPa) and LiBC (isotropic cell compressibility with B ∼ 190 GPa). Li deficiency increases the conductivity; however, the temperature-dependent conductivity is dominated by the thermal excitation of carriers in a strongly disordered regime with well-defined localized states.