CaO-CuO system at high oxygen pressure: Bulk synthesis and transport properties of Ca₁₄Cu₂₄O₄₁

CaO-CuO system has been investigated at high oxygen pressure. Only two ternary compounds, Ca0.83CuO2 and Ca14Cu24O41, were found to be stable at P(O2) = 500 bar. Ca14Cu24O41 has been synthesized as a bulk phase for the first time. The formation of this phase occurs only in a very narrow range of temperature and oxygen pressure. Resistivity measurements at high pressure from 3 to 8.5 GPa show superconducting transition in the whole range of pressures. Magnetic properties of this compound at ambient pressure have been also studied. © 2001 Elsevier Science B.V.