超高压下CsBr的结构与相变

 采用金刚石对顶压砧高压装置（DAC）、同步辐射X光源和能散法，对CsBr粉末样品进行了原位高压X光衍射实验，最高压力达115 GPa。观测到在53 GPa左右压力下，CsBr的最强衍射峰(110)劈裂成两个峰，标志了简单立方结构向四方结构的转变；在0至最高压力范围内（相应于V/V₀为1至0.463）测量了晶轴比c/a；在115 GPa内未观测到样品的金属化现象。

THE STRUCTURE AND PHASE TRANSITION FOR CsBr UNDER ULTRAHIGH PRESSURE

In situ energy dispersive X-ray diffraction measurements on CsBr under pressure up to 115 GPa have been performed by using pressure device－diamond anvil cell (DAC) with synchrotron source. It is determined that the structure of CsBr is changed from simple cubic phase to tetragonal phase at about 53 GPa marked by the splitting of its strongest diffraction line (110) into two parts: (011) and (110). The lattice parameter ratio c/a has been measured from p=0 to the maximum pressure (corresponds to V/V₀ range of 1～0.463). No pressure-induced metallization transition has been observed at higher pressure up to 115 GPa.