Intermetallic borocarbides: electronic structure, chemical bonding, and properties

In 1994, the superconductivity of intermetallic borocarbides (IBC) of composition LnM₂B₂C, where Ln is a rare-earth metal and M is Ni or Pd, was discovered. This discovery stimulated numerous works on the synthesis of new quaternary borocarbide phases and solid solutions based on them and studies of their crystal chemistry and magnetic, superconducting, and transport properties. Almost simultaneously, investigations of the fundamental electronic properties of IBC and specific chemical bonding in this new class of materials have been initiated. The results of theoretical and experimental investigations in these fields are summarised. The bibliography includes 179 references.