X-Ray Diffraction Studies on CsBr under High Pressure

In situ high pressure X-ray diffraction experiments have been carried out on CsBr using energy dispersion method with synchrotron radiation source. The pressure was generated by the high pressure device－diamond anvil cell (DAC). The pressures up to 64.4 GPa were determinded by the diffraction data of Pt used as an inner pressure standard, whose EOS is known. The results indicate that the original sample AsBr is in simple cubic structure at room temperature and atmosphere pressure, its lattice parameter =0.428 5 nm. The structure of CsBr is changed to tetragonal phase at high pressure, marked by the splitting of the diffraction lines (110) and (211) after 51.3 GPa.