Prediction of metastable layered Li-Cu-BC and Li-Ag-BC accessible via topochemical reactions

Hole doping of the only two presently known stoichiometric metal borocarbides with honeycomb layers, LiBC and MgB₂C₂, has been considered a promising pathway to attain high-T_c phonon-mediated superconductivity at ambient pressure. In an effort to extend this materials class, we investigate the possibility of obtaining new ternary or quaternary metal borocarbides via topochemical synthesis. Our ab initio thermodynamic stability analysis indicates that the reaction of Li_xBC with MCl (M = Cu or Ag) may lead to the formation of new metastable Li-Cu-BC and Li-Ag-BC materials.