引用本文:
【打印本页】   【HTML】   【下载PDF全文】   View/Add Comment  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 1302次   下载 1520 本文二维码信息
码上扫一扫!
分享到: 微信 更多
Grain Growth Kinetics of BaTiO3 Nanocrystals During Calcining Process
Xiao-lan Song¤,Xi He,Hai-ping Yang,Yi-xin Qu,Guan-zhou Qiu
Author NameAffiliationE-mail
Xiao-lan Song¤ School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China xlsong@hnu.cn, 
Xi He School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China  
Hai-ping Yang School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China  
Yi-xin Qu College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China  
Guan-zhou Qiu School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China  
Abstract:
BaTiO3 nanocrystals were synthesized by sol-gel method using barium acetate (Ba(CH3COO)2) and tetrabutyl titanate (Ti(OC4H9)4) as raw materials. Xerogel precursors and products were characterized by means of thermogravimetric/differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD) and transmission electron microscope (TEM). The influence of the calcination temperature and duration on the lattice constant, the lattice distortion, and the grain size of BaTiO3 nanocrystals was discussed based on the XRD results. The grain growth kinetics of BaTiO3 nanocrystals during the calcination process were simulated with a conventional grain growth model which only takes into account diffusion, and an isothermal model proposed by Qu and Song, which takes into account both diffusion and surface reactions. Using these models, the pre-exponential factor and the activation energy of the rate constant were estimated. The simulation results indicate that the isothermal model is superior to the conventional one in describing the grain growth process, implying that both diffusion and surface reactions play important roles in the grain growth process.
Key words:  BaTiO3 nanocrystal, Sol-gel method, Grain growth kinetics
FundProject:其它
Grain Growth Kinetics of BaTiO3 Nanocrystals During Calcining Process
宋晓岚¤,何希,杨海平,屈一新,邱冠周
摘要:
以醋酸钡和钛酸四丁酯为原料,采用溶胶-凝胶法合成了纳米BaTiO3粉体;运用差示/热重、X射线衍射及透射电镜对前驱体凝胶和产物进行了表征,并根据XRD结果,研究了纳米BaTiO3的晶格常数、晶格畸变度和晶粒尺寸随焙烧温度及时间的变化。结果表明,焙烧温度与时间对纳米BaTiO3晶格常数的影响不明显;随焙烧温度或时间的延长,纳米BaTiO3的晶格畸变度减小,晶粒尺寸增大,但晶格畸变度和晶粒尺寸更敏感于焙烧温度. 基于扩散控制机理的传统模型探讨了焙烧过程纳米BaTiO3晶粒生长动力学,得出其晶粒生长指数为7,晶粒生长活化能为75.49 kJ/mol. 将基于扩散与反应共同控制机理的新型等温模型应用于本研究中,结果表明,新型等温模型更能真实地反映纳米BaTiO3焙烧过程中的晶粒生长行为,说明纳米BaTiO3晶粒生长过程同时受溶质扩散和表面反应控制,其藕合晶粒生长活化能为27.23 kJ/mol.
关键词:  BaTiO3纳米晶,溶胶-凝胶法,焙烧,晶粒生长动力学
DOI:10.1088/1674-0068/21/03/295-300
分类号: