熔盐法合成Bi_3NbTiO_9的晶粒生长动力学研究  

Investigations on Growth Kinetics of Bi_3NbTiO_9 Particles Synthesized by Molten Salt Method

作　　者：李宝让[1] 张乃强[1] 刘东雨[1] 徐鸿[1] 

机构地区：[1]华北电力大学电站设备状态监测与控制教育部重点实验室,北京102206

出　　处：《人工晶体学报》2011年第4期983-989,共7页Journal of Synthetic Crystals

基　　金：华北电力大学博士基金;教育部创新团队计划(PCSIRT0720)

摘　　要：本文采用熔盐法,利用氯化钾作助熔剂成功合成了Bi3NbTiO9多晶粉体。并在此基础上,利用经典的动力学方程系统研究了Bi3NbTiO9多晶粉体在熔盐合成过程中的晶粒生长动力学。结果表明:利用熔盐方法合成Bi3NbTiO9多晶粉体的生长过程,可以划分为高温和低温两个阶段,并且在不同的阶段存在不同的生长机制。进一步对熔盐法合成多晶陶瓷粉体的形核和长大两个反应阶段进行研究,结果表明:粉体的形核过程遵循JMAK方程。低温阶段即低于900℃时,Bi3NbTiO9晶粒的长大速率较小,生长主要依赖于扩散;900℃以后晶粒的长大速率和晶粒生长激活能均显著增加,生长主要依赖于界面反应;高温生长的后期会发生明显的异常晶粒长大。Bi3NbTiO9 powders were successfully synthesized by molten salt method using KCl as flux.The particle growth kinetic was studied by typical dynamics equation during the synthesis processing.The results indicated that the particle growth process could be divided into two stages obviously,in which different growth mechanisms were obeyed.Investigations on two stage including the nucleation and followed growth process indicated that JMAK equation was obeyed at the initial of nucleation formation.The particle growth rate was relatively low at temperature lower than 900 ℃ and the growth process was mainly dependent upon the atom diffusion.When the temperature was higher than 900 ℃,both the growth rate and activation energy increased obviously.The corresponding particle growth was controlled by the interface reaction mechanism.Especially,obvious abnormal grain growth could be observed at the final stage of particle growth at high temperature.

关 键 词：Bi3NbTiO9 熔盐法 生长动力学 

分 类 号：TB332[一般工业技术—材料科学与工程]