Bulk modulus of CeO2 and PrO2-An experimental and theoretical study

The high-pressure structural behaviour of CeO2 and PrO2 has been investigated by synchrotron X-ray diffraction at pressures up to 20 and 35 GPa, respectively. The experiments are accompanied by first principles calculations using the self-interaction corrected local spin density (SIC-LSD) approximation. The experimental values for the zero-pressure bulk modulus of CeO2 and PrO2 are 220(9) and 187(8) GPa, respectively. Our calculations reproduce the lattice constants with good accuracy, but find identical bulk modulii for CeO2 (176.9 GPa) and PrO2 (176.8 GPa).