Structural stability of infinite-layer CaCuCO2 under high pressure

In situ high-pressure energy dispersive X-ray diffraction measurements on polycrystalline powder CaCuO2 with an infinite layer structure (IL CaCuO2) have been performed by using diamond anvil cell (DAC) instrument with synchrotron radiation. The results suggest that the crystal structure of IL CaCuO2 is stable under pressure up to 30 GPa at room temperature. According to Birch-Murnaghan equation of state, assuming pressure derivativeB′0 = 4, the bulk modulusB 0=181 ± 9 GPa is obtained.