  Polycrystalline samples of LiBC compounds, which were predicted as possible
candidate for high-Tc superconductivity, have been synthesised by a flux method
and investigated by means of electrical resistivity and magnetic
susceptibility. Scanning electron microscopy and X-ray diffraction patterns
showed a plate-like morphology and a single-phase nature of LiBC samples for
starting composition of Li1.25BC (flux composition). The lattice constants a, c
display a systematic variation with x and has maximum volume of the hexagonal
unit cell at x = 1.25. Electrical resistivity measurements revealed an
extrinsic semi-conducting behaviour of the single-phase LiBC with an activation
energy of 18 meV and a maximum specific resistivity of 2.5 Wcm at 300 K. In
contrast to the theoretical prediction of high Tc, no superconducting features
were detected down to 2 K both, by measurements of electrical resistivity and
magnetic susceptibility.
