Proceedings of the Annual Joint Conference, the Mineralogical Society of Korea and the Petrological Society of Korea,
May 23-24, 2013, Daejeon, Korea
(사)한국광물학회․한국암석학회
2013년 공동학술발표회 논문집 - 81 -
비정질 산화물 표면의 질서도 규명 Order in Oxide Glass Surfaces
이성근1
1서울대학교 지구환경과학부 지구물질과학연구실([email protected])
The structure of the surface of glasses remains an unsolved question in the modern physical and chemical sciences. The lack of knowledge is in stark contrast to the wealth of information available on crystalline analogues, for which the structure of the surfaces are known to be often dramatically different from that of the bulk oxides. The knowledge gap derives from the fact that conventional surface-sensitive probes of crystals [e.g., vibrational spectroscopies, x-ray and/or electron diffraction and microscopy, and x-ray absorption spectroscopy, etc.] have limited usefulness for exploring the detailed short-range structures of surfaces of oxide glasses, and this poses major challenges for directly probing thickness-induced structural changes in amorphous oxides. Here, we report the solid-state NMR results for amorphous oxide surfaces. The local structures of the amorphous surfaces are drastically different from those of bulk, highlighted by crystal-like order within the glass surface. The observed trend of decreasing disorder on the glass surface is expected to be general to other glass forming liquids. The current results provide microscopic insights into geochemical processes, such as weathering and formation of ocean crust at the Earth and planetary surfaces where interactions between amorphous oxide surfaces and fluids are prevalent.
