Medium range structure and dynamics of glass and molten glass

玻璃和熔融玻璃的中程结构和动力学

基本信息

批准号：
10450332
负责人：
YOKO Toshinobu
金额：
$ 9.02万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10450332/
关键词：
Medium range structure Glass melt Fragility of glass Pair function method Local atomic structure Thermal expansion Molecular dynamics X-ray radial distribution function analysis 高温X線回折ガラス構造短距離秩序動径分布解析 Unixプログラム

项目摘要

In this study, structural analysis of glass melts at high temperatures (〜1600℃) by means of X-ray diffraction has been dealt with. First, the principle and procedures of X-ray radial distribution function (RDF) analysis are described in detail. Second, the advantages of a pair function method and a molecular dynamics (MD) calculation method are also mentioned in detail, when they are used to interpret the obtained experimental RDF data. The X-ray diffraction apparatus used in this work is stated especially emphasizing that the photon counter with a high energy resolution such as Si(Li) solid state detector (SSD) should be used in order to obtain highly resolved RDF curves.The results obtained are as follows. First, the common computer programs written in C-language which made it possible to process the raw data and to calculate the RDF curves were developed using a Sun Ultra 5 workstation which is a UNIX machine. These programs are available on demand to anyone who wants to use them. S … More econd, structure analysis has been performed on SLS(16Na_2O 10CaO 74SiO_2) glass which is a model glass of commercial green glass pane in order to check the programs developed in this work. A well-resolved RDF curve was obtained for the room-temperature glass. Each peak was assigned to corresponding atomic pairs : Si-O at 0.164 nm, Na-O, Ca-O around 0.23 nm, O-O at 0.27 nm, Si-O-Si at 0.31〜0.32 nm and so on. It has been confirmed that they work perfectly. Then, the structure of SLS glass melt placed on a ZrO_2-dispersed Pt-10%Rh ribbon-heater(FKS16, Furuya Metals Co.) was analyzed at 1500℃ using a high temperature furnace in a similar way to that of the same glass at room temperature. Both the X-ray RDF analysis and MD calculation revealed that there is no distinct structural difference between the glass and melt, in other words, the network structure consisting of SiO_4 tetrahedra remains basically unchanged on melting. In this respect, the present soda-lime silicate glass can be classified into the "strong glass". It is also found from the MD calculation that the peaks due to the Na-O and Ca-O pairs become very broad and expand to the longer distance on melting, while the Si-O bondlength and the Si-O-Si bond angle remain almost unchanged. This result clearly indicates that the thermal motion of Na^+ and Ca^<2+> ions becomes remarkable at higher temperatures, leading to the thermal expansion. We can say that the thermal expansion of soda-lime silicate glasses is mainly governed by the thermal motion of Na^+ ions. Less

在此螺柱中，详细描述了X射线径向分布函数（RDF）分析的PRINC三和步骤，其次是配对函数方法的优点和分子动力学（MD）计算方法，还确定了获得的经验丰富的RDF数据. The X-Ray Diffraction Apparatus USed in this work is stated especially EMPHASIZING THE PHOTON COUNTER WITH A COUTH AS SI (LI) Solid State Detector (SSD) SHOULD BE USED TO OBTAIN HIGHLY d RDF CURVES.THE RESULTS OBTAINED ARE as FOLLOWS. First ，C -Clanguage中的常见计算机程序可以使用5个工作站来开发RDF曲线并计算RDF弯曲。在SLS上进行了更多的结构分析（16NA_2O 10CAO 74SIO_2），它是模型的玻璃绿色胶水窗格，以检查该工作中的AMS。每个峰都被分配到Correspong对：SI-O在0.164 nm，Na-O，Ca-O-O时为0.27 nm，SI-O-SI在0.31〜0.32 N时，确认它们的结构是完美的。在1500°C上使用高温炉以类似的方式放置在室温下的玻璃，换句话说，Sio_4 Tetrahedra的网络结构构造基本上保持不变熔化。 ^<2+>离子在较高的温度下变得异常，导致周四的膨胀。