Author/Authors :
Smaalen، نويسنده , , Sander van and Dinnebier، نويسنده , , Robert E and Milletich، نويسنده , , Ronald and Kunz، نويسنده , , Martin and Holleman، نويسنده , , Iwan and von Helden، نويسنده , , Gert and Meijer، نويسنده , , Gerard، نويسنده ,
Abstract :
We report the pressure dependence of the cubic lattice parameter of (CO)xC60 at different temperatures, as determined by X-ray powder diffraction. In the measured range of pressures from 0.2 to 2 GPa, the volume is found to depend linearly on the pressure. The extrapolated volume bulk modulus of the ordered phase at room temperature is found to be K0=−V dP/dV=31.5(5) GPa. The bulk modulus at T=150 K is found as K0=26.9(5) GPa. The greater stiffness at higher temperature is explained by the entropic contribution of the CO molecules to the bulk modulus.
