Structural behavior of non-oxide perovskite superconductor MgCNi3 at pressures up to 32Â GPa

We report the pressure dependence of the structural parameters of the non-oxide perovskite superconductor MgCNi3 up to 32 GPa using a diamond anvil cell and synchrotron X-rays at room temperature. The structure of the compound remains in the Pm-3m cubic symmetry throughout the pressure range. The bulk modulus B0=156.9±0.2GPa with B0′=9.8 obtained by fitting the pressure-volume data is in good agreement with theoretical calculations reported earlier. An anomalous shift of the (1 1 1) and (2 0 0) lines observed above 9 GPa indicates a possible local short range distortion that is consistent with earlier studies.