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

在这项研究中，已经处理了X射线衍射对高温（〜1600℃）处玻璃熔体的结构分析。首先，详细描述了X射线径向分布函数（RDF）分析的原理和过程。其次，当用来解释获得的实验性RDF数据时，还提到了配对函数方法和分子动力学（MD）计算方法的优点。该工作中使用的X射线衍射设备特别强调，应使用具有高能量分辨率的光子计数器，例如Si（li）固态检测器（SSD），以获得高度分辨的RDF曲线。所获得的结果如下。首先，使用C语言编写的常见计算机程序，这使得可以使用Unix机器的Sun Ultra 5工作站来开发原始数据并计算RDF曲线。这些程序可按需使用，任何想要使用它们的人。 S…更经济的结构分析已在SLS（16NA_2O 10CAO 74SIO_2）玻璃上进行，该玻璃是商用绿色玻璃窗格的型号，以检查这项工作中开发的程序。为室温玻璃获得了良好的RDF曲线。将每个峰分配给对应于0.164 nm，Na-O，Ca-O在0.23 nm左右，O-O在0.27 nm，Si-O-SI时，在0.31至0.32 nm等处的Si-O对应。已经确认它们的工作正常。然后，将SLS玻璃的结构熔化在Zro_2分散的PT-10％RH Ribbon-Heater（FKS16，Furuya Metals Co.）上，以1500℃分析了与室温下相同玻璃的高温炉。 X射线RDF分析和MD计算都表明，玻璃和熔体之间没有明显的结构差异，换句话说，由SIO_4四面体组成的网络结构基本上在熔化方面保持不变。在这方面，目前的苏打石硅玻璃可以分为“强玻璃”。还可以从MD计算中发现，由于Na-O和Ca-O对引起的峰变得非常宽，并扩展到更长的熔化距离，而SI-O键长和SI-O-SI键角几乎保持不变。该结果清楚地表明，在较高温度下，Na^+和Ca^<2+>离子的热运动变得显着，从而导致热膨胀。我们可以说，苏打石硅玻璃的热膨胀主要受Na^+离子的热运动控制。较少的