第7回フロンティア材料研究所講演会 (Eleonora Kulik)
開催日時 | 2016年06月30日 13:30 -14:00 |
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開催場所 | R3棟1階 会議室 |
主催 | フロンティア材料研究所 |
連絡先 | 若井 史博 教授(内線:5361) |
プログラム等
講師: Eleonora Kulik
(Deutsches Elektronen-Synchrotron, Germany)
演題: "Thermal expansion of coesite: A synchrotron X-ray diffraction study from 100 K up to 1000 K"
講演概要:
Coesite is the densest silica polymorph in which silicon is tetrahedrally coordinated by oxygen .However, contrary to other low pressure forms of SiO2, coesite does not undergo α-β transition at least up to 1776 K, it also exhibit much lower thermal expansion than quartz and crystobalite. In this work high-temperature structural features of synthetic coesite and its behavior at the microscopic level have been investigated by X-ray powder diffraction . We observed that the thermal expansion of coesite is strongly anisotropic and negative along a c axis . It leads to a very low volume expansion by only 0.7% in the considered temperature range between 100 K and 1000 K. For the material research and ceramic industry the importance of such kind of materials is in their widespread use in high anti-thermal shock applications.