单斜辉石中缺陷OH结合机理的变温红外光谱实验研究  

FTIR investigations of OH defects in clinopyroxenes at varying temperatures and their incorporation mechanisms

作　　者：杨燕[1] 夏群科[1] 李佩[1] 郝艳涛[1] 杨晓志[1] 

机构地区：[1]中国科学院壳幔物质与环境实验室

出　　处：《岩石矿物学杂志》2007年第5期429-435,共7页Acta Petrologica et Mineralogica

基　　金：中法先进研究计划(T05-02);国家自然科学基金(40473007);教育部"新世纪优秀人才支持计划";中国科学院研究生科学与社会实践项目;中国科学技术大学研究生创新基金

摘　　要：利用变温红外光谱及偏振实验的结果，依据晶体化学理论及键长与振动频率的关系，从热膨胀速率这一新的角度探讨了单斜辉石中缺陷OH的结合机理。单斜辉石中OH的红外吸收峰主要有3组：3600～3620cm^-1、3500-3540cm^-1和3445-3465cm^-1。第1组峰对应的的OH结合方式是Si^4＋＋O2-＋1／2H2←→Al^3＋＋OH-，第3组峰对应的OH结合方式是H填充M2空位。第2组峰对应的OH结合方式复杂，可能和多个位置有关。第2和第3两组OH偶极的振动方向一致，都是M1和M2的共棱O2—O1，而第1组OH偶极的振动方向则是M2的O2—O3棱。Based on FTIR experiments of diopsides and omphacites at varying temperatures, this paper discussed the incorporation mechanisms of OH defects in clinopyroxene minerals from a new point of view, i.e. , thermal expansion. There are three groups of OH absorption bands in clinopyroxene minerals, namely, 3 600 3 620cm^-1,3 500- 3 540 cm^-1, and 3 445-3 465cm^-1. The OH incorporation mode of Group 1 bands is Si4 ＋ ＋ 02- ＋ 1/2H2←→Al^3 ＋ ＋ OH^-, while the M2 vacancy is responsible for the OH incorporation mode of Group 3 bands. The OH incorporation mode of Group 2 bands is complex and might be related to several different positions. The OH dipole vibration direction of Group 2 bands is the same as that of Group 3 bands, along the shared edge of M1 and M2 polyhedra, O2-O1. And the OH dipole of Group 1 bands vibrates between O2 and O3 along the edge of M2 polyhedron.

关 键 词：单斜辉石 红外光谱 变温 OH 结合机理 

分 类 号：P578.954[天文地球—矿物学] O657.33[天文地球—地质学]