褐钇铌矿族矿物变生非晶态的高温相变研究  

A STUDY ON HIGH-TEMPERATURE PHASE TRANSITION OF METAMICT FERGUSONITE GROUP MINERALS

作　　者：贡伟亮[1] 

机构地区：[1]中国科学院地球化学研究所,贵阳550002

出　　处：《矿物学报》1991年第1期1-8,T001,共9页Acta Mineralogica Sinica

基　　金：国家自然科学基金

摘　　要：采用高温X射线衍射分析和退火结晶实验,研究了褐钇铌矿族矿物变生非晶态的高温相变关系。确认自然界稳定存在T(四方)和M(单斜)两种变体,高温下还存在另一个四方变体T′。T,M和T′三者间关系为:相变温度受A组阳离子的平均离子半径控制。进而讨论了T和T′的结构差异,并指出相对于T′的晶格畸变是T相室温稳定的原因。此外,还讨论了变生非晶态的结构,提出了鉴定变生非晶态原生相的有效方法,并在白云鄂博矿床中鉴定出本族矿物6种12个亚种矿物,首次给出了本族矿物新成员——T-褐钕铌矿的X射线粉晶数据。In-situ high-temperature XRD and annealling recrystallization experiment were used to study the high-temperature phase transition of metamict fergusonite group minerals. Three polymorphs of the fergusonite group are recognized: M(monoclinic) and T(tetragonal) stable in nature, andT'(another tetragonal form) only stable at higher temperature. Their relationship is expressed as. The transition temperatures are dependent on the ionic radii of Group A atoms. The differences between T and T', and the structure of the amorphous state are discussed it, this paper,Additionally, six varieties and twelve subvarieties of the fergusonite group have been identified in Bayun Obo. X-ray powder diffraction data of T-fergusonite-(Nd), a new member of the fergusonite group, are given for the first time.

关 键 词：褐钇铌矿族 高温相变 高温X射线衍射 变生非晶态 退火结晶 变体 相变温度 

分 类 号：P578[天文地球—矿物学]