Chinese Acad Sci, Inst Phys, Beijing 100080, Peoples R China
; Beijing High Pressure Res Ctr, Beijing 100080, Peoples R China
; Inst High Energy Phys, Beijing 100039, Peoples R China
The perovskite-like structure compound Ca-0.85-CuCO2 has interesting structural properties: it has infinite one-dimensional edge-sharing copper-oxygen chains as well as partial occupancy of the Ca sites resulting in an incommensurate superstructure. In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder Ca0.85CuO2 have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results for the first time show that edge-sharing copper oxide Ca0.85CuO2 undergoes a structural transition at 14.5 GPa, and furthermore the structural transition is reversible.