Structural Analysis of Al_2O_3 Based High Temperature Melts

含Al_2O_3熔体的结构信息对于更好地理解晶体和炼钢过程中的固-熔体反应是很重要的。然而，这些信息是不够的，因为高温下的原位X射线衍射测量是非常困难的。本研究的主要目的是获得含Al_2O_3高温熔体的系统结构数据。以纯Al_2O_3(Waseda et al，1994)的结构数据为基础，用普通角色散X射线衍射(ADXD)和能量色散X射线衍射(EDXD)技术系统地分析了Al_2O_3-SiO_2-Na_2O系统的熔体结构。众所周知，EDXD技术是一种强大的技术，它可以获得250 nm~(-1)以上的宽干涉函数，这使我们能够获得精确的径向分布函数(RDF)。实验RDFS清楚地表明，随着SiO_2和Na_2O的加入，Al_2O_3熔体中AlO_6的局部结构单元转变为AlO_4的局部结构单元。这些有用的结果只有通过ADXD和EDXD分析相结合才能得到。本文的分析可望应用于更广泛的结构分析领域。

The structural information on the melt containing Al_2O_3 is important for the better understanding of solid-melt reactions of the crystal and steel making process. However, such information is not enough because in-situ X-ray diffraction measurement at high temperature is very difficult. The main purpose of the present research project is to obtain the systematic structural data of high temperature melts containing Al_2O_3Basing on the structural data of pure Al_2O_3 (Waseda et al, 1994), the melt structure in the Al_2O_3-SiO_2-Na_2O system was systematically analyzed by the common angular dispersive X-ray diffraction (ADXD) and the energy dispersive X-ray diffraction (EDXD) techniques. The EDXD technique is known to be one of the powerful techniques which allow to get wide interference function Qi(Q) of over 250nm^<-1> and this enables us to obtain precise radial distribution functions (RDF). The experimental RDFs clearly indicate that the local structural unit of AlO_6 in the Al_2O_3 melt changes into that of AlO_4 with the addition of SiO_2 and Na_2O.These useful results are obtained only by the combination of ADXD and EDXD analyzes, presently developed. The present analysis are expected to be applied to the wider field of structural analyzes.