白钨矿的原位高压X射线衍射研究  

In-situ High-Pressure X-Ray Diffraction of Natural Scheelite

作　　者：刘迎新[1,2] 秦善[2] 李晓东[3] 李延春[3] 刘景[3] 

机构地区：[1]地质过程与矿产资源国家重点实验室中国地质大学,北京100083 [2]造山带与地壳演化教育部重点实验室北京大学地质学系,北京100871 [3]中国科学院高能物理研究所同步辐射室,北京100049

出　　处：《矿物学报》2009年第4期524-529,共6页Acta Mineralogica Sinica

基　　金：国家自然科学基金(批准号:40672024);中国科学院知识创新重要方向项目(KJCX2-SW-N20)

摘　　要：使用金刚石对顶砧高压装置(DAC)和同步辐射光源,对天然白钨矿进行了原位高压能量色散X射线衍射(EDXD)研究,实验最高压力为16.0GPa。在实验压力范围内观察到了一次白钨矿结构→钨锰铁矿结构的可逆相变:压力小于5.3GPa时为白钨矿结构(I41/a),在5.3～12.3GPa压力区间内为白钨矿结构与钨锰铁矿结构(P2/c)并存,大于12.3GPa时完全相变为钨锰铁矿结构。从键长、配位数和配位多面体角度对白钨矿→钨锰铁矿结构的相变机制进行了解释。In-situ high-pressure energy dispersive X-ray diffraction experiments on natural seheelite （CaWO,） have been carried out at room temperature by using DAC device with a synchrotron radiation source at 4W2 High-Pressure Station of Beijing Synchrotron Radiation Facility. In pressures higher than 16. 0 GPa, a reversible phase transition from scheelite-strueture to wolframite- structure was observed. With increasing pressure, CaWO4 kept the scheelite- structure until 5.3 GPa, and then had a coexistence with scheelite- and wolframite-structures between 5. 3 GPa and 12. 3 GPa, and finally completely transformed to wolframite-structure at pressures above 12. 3 GPa. The mechanism of the phase transition from scheelite-to-wolframite was also explained in the views of bond length, coordinate number and coordinate polyhedron.

关 键 词：白钨矿 同步辐射 高压 X射线衍射 相变 

分 类 号：O521.2[理学—高压高温物理] P574[理学—物理]