Note on the Li-Cu-O system

Article abstract of DOI:10.1016/0022-5088(91)90233-T

In the Li-Cu-O system two new ternary phases have been found, tentatively described by the stoichiometries LiCu₃O₃ and LiCu₂O₂, and both containing Cu¹ and Cu¹¹. They exhibit p-type 'hopping' conduction owing to localized charge carriers. Their powder patterns are successfully indexed on high-symmetry cells where the dimensions depend on a slightly variable stoichiometry. LiCu₃O₃ is tetragonal with a = 2.815 (·√2) angstrom and c = 8.88 angstrom. LiCu₂O₂ is orthorhombic with a = 5.72 angstrom, b = 2.86 angstrom and c = 12.4 angstrom. Li₃Cu₂O₄, containing Cu¹¹ and Cu¹¹¹, is indexed on a C-centred monoclinic cell: a = 9.958 angstrom, b = 2.777, c = 7.281 angstrom and β = 118.77°. The solubility of lithium in CuO is maximally Li_0.06Cu_0.94O for supersaturation at 1100 K. The equilibrium solubility limit is about Li_0.02Cu_0.98O, for which the solid solution is still semiconducting. The temperature dependence of the magnetic susceptibility is similar to that of pure CuO but T_N is considerably lower.