变生锆石的^(29)Si MAS NMR与红外光谱研究  

^(29)Si MAS NMR AND INFRARED SPECTROSCOPIC STUDIES ON METAMICT ZIRCONS

作　　者：林传易[1] 郭九皋[1] 郭建新[1] 李丽云[1] 田淑贵 

机构地区：[1]中国科学院武汉物理研究所波谱与原子分子物理国家重点实验室,武汉430071 [2]中国科学院地球化学研究所广州分部,广州510640

出　　处：《波谱学杂志》1993年第4期377-383,共7页Chinese Journal of Magnetic Resonance

基　　金：国家自然科学基金

摘　　要：关于锆石变生过程中SiO_4四面体行为的信息对于了解变生态结构及变生过程机理有重要意义。虽然有人推测,在变生过程中,伴随着ZrO_8多面体上氧空位的产生可能同时发生SiO_4四面体的聚合,但迄今并无直接的实验证据证明这一假设。本文的^(29)Si MASNMR研究表明,在锆石变生的最初阶段,Si的局部结构环境没有明显的变化,但在中等变生程度的样品中,探测到Q^3和Q^4Si环境,这是一个有力的证据,支持随着变生程度增加SiO_4四面体发生逐步聚合的假设。红外光谱的结果也显示,变生锆石中可能有无定形的氧化硅畴存在。Information about the behavior of silicate groups during metamictization of zircon is important for a full understanding of the structure of metamict state as well as the mechanism of the process of metamictization of this mineral. Although there is speculation that the creation of 0 vacancies may lead to a progressive polymerization of SiO4 tetrahedra[7] , no direct experimental evidence supports it up to date. The 29Si MAS NMR results of the present work show that no significant changes in the local structural environment of Si occur at the initial stage of metamictization. However , Q3 and Q4 Si environments were detected in zircons with mediate degree of metamictization (DOM), indicating that the intrease of DOM leads to a polymerization of SiO4 tetrahedra. The products of polymerization must be amorphous because no crystalline phases other than zircon were detected by XRD. The results of infrared measurments also indicate that domains of amorphous silica may exist in metamict zircons.

关 键 词：锆石 红外光谱 MNR 变生作用 

分 类 号：O578.941[理学—粒子物理与原子核物理]