单一相荧光粉基质体系钡镥硅氧化物相图及热力学

项目名称： 单一相荧光粉基质体系钡镥硅氧化物相图及热力学

项目编号： No.51304086

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 矿业工程

项目作者： 叶信宇

作者单位： 江西理工大学

项目金额： 25万元

中文摘要： 新发现的紫外光激发单一相白光荧光粉具有低色温、高显色、色坐标可调、较高光效等优点而显现出重要的应用前景，但其基质体系钡镥硅氧化物相图及热力学知识严重缺乏阻碍了材料制备工艺改进和性能提升。针对该体系相图实验低温下固相内的扩散速度慢、高温液相线难测准而导致观测不到真正平衡组成的核心问题，本项目采用金属醇盐的Sol-Gel 过程获得均匀性试料；结合微结构观测和配备"撒样法"的相态XRD确定平衡加热时间；由点阵常数和极限斜率确定和评估固溶体等，提升相图低温区域准确性；在此基础上，将改良的短程有序-对近似-似化学模型与双亚晶格模型结合，建立更符合溶液内部物理特征的高温液相新模型，优化计算高温区域溶解度间隙等关键部分，以至增强对高元系的兼容能力。研究获得的自洽相图与热力学、低温相平衡研究方法、热力学模型及建立方法，将为白光荧光粉的性能优化提供急切需要的理论基础，同时也为冶金领域相关研究提供有益借鉴。

中文关键词： 氧化物体系；相图；热力学；荧光粉；

英文摘要： The novel single-phase full-color phosphor suitable for UV-LED excitation is expected to apply in white LEDs due to its low color temperature, high color rendering index, adjustable color coordinates and high luminous efficiency. However, recent work to optimize material preparation and promote luminescence of the single-phase full-color phosphor encountered some difficulties due to the lack of phase relationship and thermodynamics of BaO-Lu2O3-SiO2 matrix system. Actually, it is very difficult to find the real phase equilibria at low and high temperature in BaO-Lu2O3-SiO2 system and its sub-systems due to slow diffusion rate within the solid phases and the difficulty to measure liquidus line. This project aims to slove these problems. On one hand, high-quality phase diagram especailly in the low temperature region will be contructed by the use of a series of advanced methods, such as obtain dry but uniform specimens by the Sol-Gel reaction of metal alkoxides,acquire the heating times of phase balance by microstructure observation and XRD tests equiped with a new sample-preparation-method, and determine the religions of solid solution accurately by measurement of lattice constants and the calculation of limiting slope. On the other hand, the Modified Quasi-chemical Model in the Pair-approximation for Short-range

英文关键词： oxide systems；phase diagram；thermodynamics；phosphor；