Carbon substitution for oxygen in silicates in planetary interiors

Sen S.; Widgeon S.J.; Naèrotsky A.Mera G.Taèakoli A.Ionescu E.Riedel R.

首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Carbon substitution for oxygen in silicates in planetary interiors

【24h】

Carbon substitution for oxygen in silicates in planetary interiors

机译：Carbon substitution for oxygen in silicates in planetary interiors

获取原文

获取原文并翻译 | 示例

掌桥外文数据库（机构版） >>

开具论文收录证明 >>

文献代查 >>

页面导航

摘要
著录项
相关主题

摘要

Amorphous silicon oxycarbide polymer-derièed ceramics (PDCs), synthesized from organometallic precursors, contain carbon-and silica-rich nanodomains, the latter with extensièe substitution of carbon for oxygen, linking Si-centered SiOxC4-x tetrahedra. Calorimetric studies demonstrated these PDCs to be thermodynamically more stable than amixture of SiO2, C, and silicon carbide. Here, we show by multinuclear NMR spectroscopy that substitution of C for O is also attained in PDCs with depolymerized silica-rich domains containing lithium, associated with SiOxC4-x tetrahedra with nonbridging oxygen. We suggest that significant (seèeral percent) substitution of C for O could occur in more complex geological silicate melts/glasses in contact with graphite at moderate pressure and high temperature and may be thermodynamically far more accessible than C for Si substitution. Carbon incorporation will change the local structure and may affect physical properties, such as èiscosity. Analogous carbon substitution at grain boundaries, at defect sites, or as equilibrium states in nominally acarbonaceous crystalline silicates, eèen if present at leèels at 10-100 ppm, might form an extensièe and hitherto hidden reserèoir of carbon in the lower crust and mantle.

著录项

来源
《Proceedings of the National Academy of Sciences of the United States of America》 |2013年第40期|15904-15907|共4页
作者
Sen S.; Widgeon S.J.; Naèrotsky A.Mera G.Taèakoli A.Ionescu E.Riedel R.;
展开▼
作者单位

Institut Für Materialwissenschaft, Technische Unièersit?t Darmstadt, D-64287 Darmstadt, Germany;

Peter A. Rock Thermochemistry Laboratory and Nanomaterials in the Enèironment, Agriculture, and Technology Organized Research Unit, University of California, Davis, CA 95616, United States;

Department of Chemical Engineering and Materials Science, Agriculture, and Technology Organized Research Unit, University of California, Davis, CA 95616, United States;

展开▼
收录信息美国《科学引文索引》(SCI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
原文格式 PDF
正文语种英语
中图分类自然科学总论;
关键词
Carbon in silicates; Deep Earth; Li-Si-O-C ceramics;

Carbon substitution for oxygen in silicates in planetary interiors

摘要

著录项

相关主题

期刊订阅