摘要
利用同步辐射能量色散X射线衍射(EDXD)方法和金刚石对顶砧(DAC)高压技术对采于四川平武的锡石进行原位高压(达24.0 GPa)结构研究发现:压力加载过程中,锡石在13.8 GPa时发生了从金红石型结构(P 42/m nm)到C aC l2型结构(P nnm)的位移式相变;在19.9 GPa时又由C aC l2型结构相变为黄铁矿型结构(P a3),此相变为重构式相变。对于第Ⅳ主族元素氧化物(S iO2,G eO2,SnO2和PbO2)及过渡金属氧化物(M nO2和R uO2)的高压行为进行了讨论,它们具有相似的高压相变序列,这些成果对与斯石英同构氧化物的高压行为研究提供了有价值的参考。
The in situ high-pressure structure of natural cassiterite,obtained from Pingwu in Sichuan provlnce,has been studied by using synchrotron radiation energy dispersive X-ray diffraction and diamond anvil cell at the pressure up to 24.0 GPa. Two pressure-induced phase transitions, from futile-type (P42/mnm) to CaCl2-type (Pnnm) to pyrite-type (Pa-3) at the pressures of 13.8 GPa and 19. 9 GPa, were experimentally observed. The dioxides of the group IVb metals (SiO2, GeO2, SnO2, PbO2), MnO2, and RuO2 have a similar sequence of phase transitions under high-pressure. In addition, this research would be potentially helpful for the understanding of high pressure behavior of other stishovite-type oxides.
出处
《矿物岩石》
CAS
CSCD
北大核心
2006年第2期10-15,共6页
Mineralogy and Petrology
基金
国家自然科学基金项目(40272023)
国家自然科学基金重大项目(10299040)
关键词
锡石
高压
结构
相变
同步辐射
X射线衍射
cassiterite
high-pressure
structure
phase trancition
synchrotron radiation
X-ray diffraction