【摘要】 利用同步辐射X射线衍射及拉曼光谱技术对葡萄石分别进行了原位高温及原位高压实验。原位高温实验结果表明葡萄石的热膨胀系数为K=1. 77（3）×10^-5K^-1,轴向热膨胀系数具有各向异性（α_a<α_b<α_c）,葡萄石在1073K时开始发生脱水反应,分解为钙长石及硅灰石。原位高压X射线衍射实验结果表明,在大于12. 4GPa时,葡萄石的晶胞参数发生不连续变化,可能发生了相变;在24. 0GPa左右,葡萄石发生不可逆的非晶化转变。原位高压拉曼光谱表明,葡萄石在12. 6GPa左右发生相变,这一相变很可能与其[（Si,Al）O₄]四面体中的Si发生有序排列有关。结合葡萄石的热膨胀性及压缩性,我们确定了葡萄石在高温高压下的稳定范围,这一结果对认识上地幔中含水矿物的状态以及地幔中水的来源有重要意义。更多还原

【Abstract】 The thermal behavior and compressibility of natural prehnite have been studied using synchrotron-based X-ray diffraction（ XRD） and Raman spectroscopy. In-situ high temperature XRD experiment results show an obvious axial anisotropy（ α_a< α_b< α_c） of prehnite and its thermal expansion coefficient is 1. 77（ 3） × 10^-5K^-1. The dehydration reaction of prehnite occurs at 1073 K,generating anorthite and wollastonite. In-situ high-pressure experiment results indicate that above 12. 4 GPa,the unit cell parameters of prehnite undergo discontinuous changes which may be due to a phase transition. At about 24. 0 GPa,an irreversible amorphous transition of prehnite occurs. In-situ high-pressure Raman spectroscopy observations show that a phase transition may occur at about 12. 6 GPa,which is probably caused by an ordering arrangement of Si in [（ Si,Al） O₄] tetrahedra. In combination with the thermal expansion and compressibility of prehnite,we estimated the stable range of prehnite under high temperature and pressure to understand hydrous minerals and the source of water in upper mantle.更多还原