Chemical components and microtopography of (100) surface for orthopyroxene  

作　　者：XUE Jiyue, PAN Yuguan, LUO Gufeng & LU HaipingDepartment of Earth Sciences, Nanjing University, Nanjing 210093,ChinaCorrespondence should be addressed to Xue Jiyue (e-mail: [e-mail]) 

出　　处：《Chinese Science Bulletin》2003年第9期931-934,共4页

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.40172016).

摘　　要：XPS and AES depth composition profile studies were carried on to understand chemical components of (100) surfaces for Chengde hypersthene from Hebei Province, China, and Bamble enstatite from Norway. Also, to understand the microtopography of them the AFM observation was carried on. There are obvious differences between chemical components of (100) surface and those of mineral inner. Compared with inner mineral Si4+ proportion in total cations has no distinguished variation, whereas Ca2+ and Al3+ proportions increase respectively, and Mg2+ proportion decreases. AES depth composition profile of 2000s shows that at a depth of 70 nm the atomic concentrations (%) for each element (except Si in Chengde hypersthene) slightly go up and down, but the average values have no obvious change. On the profile, the atomic concentrations (%) of Al and Si for Chengde hypersthene present a compensated relationship. Obviously, the Si and Al must have the relationship of isomorphic replacement on the (100) surface. The image of AFM shows that there is hillock growth on the (100) surface in the layered form of the polygon with 0 to several hundreds nm in thickness. The growth is a sort of secondary phyllosilicate minerals. The observation of the above-mentioned phenomenon and the recognition on the above regularities are benefit for understanding of the mechanism for weathering and water-rock reactions.XPS and AES depth composition profile studies were carried on to understand chemical components of (100) surfaces for Chengde hypersthene from Hebei Province, China, and Banible enstatite from Norway. Also, to understand the microtopography of them the AFM observation was carried on. There are obvious differences between chemical components of (100) surface and those of mineral inner. Compared with inner mineral Si4+ proportion in total cations has no distinguished variation, whereas Ca2+ and A13+ proportions increase respectively, and Mg2+ proportion decreases. AES depth composition profile of 2000s shows that at a depth of 70 nm the atomic concentrations (%) for each element (except Si in Chengde hypersthene) slightly go up and down, but the average values have no obvious change. On the profile, the atomic concentrations (%) of Al and Si for Chengde hypersthene present a compensated relationship. Obviously, the Si and Al must have the relationship of iso-morphic replacement on the (100) surface. The image of AFM shows that there is hillock growth on the (100) surface in the layered form of the polygon with 0 to several hundreds nm in thickness. The growth is a sort of secondary phyl-losilicate minerals. The observation of the above-mentioned phenomenon and the recognition on the above regularities are benefit for understanding of the mechanism for weathering and water-rock reactions.

关 键 词：化学成分 微地貌 正辉石 XPS AES深度合成剖面图 

分 类 号：P574.2[天文地球—矿物学]