Structure properties for the superconductor MgCNi3 under high pressure with synchrotron radiation

In situ high pressure energy dispersive X-ray diffraction measurements on cubic-perovskite superconduc- tor MgCNi3 under pressure up to 22 GPa have been per-formed by using diamond anvil cell with synchrotron radia-tion. We have investigated its crystal structure and com-pressibility. The results show that the structure of MgCNi3 is stable under pressure up to 22 GPa. According to Birch- Murnaghan state equation, when we assume B0 = 4, we get B0 = 267.8 7.2 GPa.