摘要
为了深入了解不同磷酸盐矿物在地球内部高压条件下的物质状态及晶体结构性质,在常温下使用金刚石对顶砧(diamond anvil cell,DAC)高压装置和同步辐射光源,对架状含水磷酸盐矿物准磷铝石进行了原位高压X射线衍射实验,最高压力达到12.2GPa。实验结果表明,随压力增大,样品的晶胞体积逐步被压缩,晶胞参数a的压缩率最小;同时,在5.5~7.3GPa和9.0~10.0GPa压力范围内,准磷铝石的晶体结构发生了改变。利用Birch-Murnaghan状态方程(K′=4)对相变前准磷铝石的体积(压力数据进行拟合,得到V_0=0.4167(标准误差为1)nm^3,K_0=55.4(1.8)GPa。
To deeply understand the state of matter and crystal structure of different phosphate minerals under high pressure in the earth interior,in-situ high-pressure X-ray diffraction（XRD）experiments were carried out on framework-shaped hydrous-phosphate metavariscite using the diamond anvil cell（DAC）device with synchrotron radiation source in Shanghai Synchrotron Radiation Facility（SSRF）.The maximal pressure recorded at room temperature is 12.2 GPa.The experimental results show that the unit-cell volume continuously decreases with increasing pressure.Two phase transitions are observed in the pressure range of 5.5-7.3 GPa and 9.0-10.0 GPa.Isothermal pressure-volume relationship of metavariscite is given by the Birch-Murnaghan equation of state,with the unit-cell volume at ambient pressure V0 being 0.4167（1）nm^3 and the bulk modulus K0=55.4（1.8）GPa by fixing the first derivative K′at 4.
出处
《中国科技论文》
北大核心
2017年第9期1054-1058,1078,共6页
China Sciencepaper
基金
高等学校博士学科点专项科研基金资助项目(20120022120015)
国家自然科学基金资助项目(41202027)
关键词
准磷铝石
同步辐射
高压
结构
metavariscite
synchrotron radiation
high-pressure
phase transition
