钛酸钡纳米颗粒聚集球的形成机理

[Article]

物理化学学报(Wuli Huaxue Xuebao )

Acta Phys.-Chim.Sin.2011,27(12),2927-2932

December Received:July 20,2011;Revised:September 21,2011;Published on Web:October 10,2011.∗

Corresponding author.Email:jiangxp64@,zhq_0425@;Tel:+86-798-8499237.

The project was supported by the National Natural Science Foundation of China (91022027,51062005,50862005).国家自然科学基金(91022027,51062005,50862005)资助项目

ⒸEditorial office of Acta Physico-Chimica Sinica

钛酸钡纳米颗粒聚集球的形成机理

展红全

江向平

*

李小红罗志云陈超李月明

(景德镇陶瓷学院材料科学与工程学院,江西省先进陶瓷材料重点实验室,江西景德镇333403)

摘要:

采用水热法合成了具有新颖结构的钛酸钡纳米颗粒聚集球.X 射线衍射(XRD)结果显示该聚集球为立

方相,随着时间的延长其结晶性增强.利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)和电子衍射(ED)谱研究了该纳米颗粒聚集球的生长特点.结果表明该聚集球是由5-8nm 的纳米颗粒定向连接生长而成,整个聚集球对外显示类单晶的现象.聚集球的大小约为60nm,随着时间的延长有长大的趋势.X 射线能谱(EDX)分析结果和Johnson-Mehl-Avrami (JMA)方程动力学模拟结果表明,在颗粒球形成初始阶段主要是Ba 2+离子的扩散成核作用占主导地位.这种“扩散成核-定向生长”的形成过程揭示了钛酸钡纳米颗粒聚集球的生长机理.关键词:

钛酸钡;JMA 方程;水热法;扩散机理;定向生长

中图分类号:

O643.12

Formation Mechanism of Barium Titanate Nanoparticle Aggregations

ZHAN Hong-Quan

JIANG Xiang-Ping *LI Xiao-Hong

LUO Zhi-Yun

CHEN Chao LI Yue-Ming

(Jiangxi Key Laboratory of Advanced Ceramic Materials,Department of Material Science and Engineering,

Jingdezhen Ceramic Institute,Jingdezhen 333403,Jiangxi Province,P .R.China )Abstract:A novel nanoparticle aggregation structure of barium titanate was obtained by the hydrothermal method.Powder X-ray diffraction (XRD)revealed that the aggregates crystallized in the cubic phase.The crystallization of the products became more significant with reaction progress.The growth characteristics of the aggregates was further confirmed by scanning electron microscopy (SEM),transmission electron microscopy (TEM),high resolution transmission electron microscopy (HRTEM),and electron diffraction (ED)spectroscopy.The aggregation was composed of many 5-8nm nanoparticles by orientation attachment and we found that the ED patterns indicated a single-crystal property for the aggregates.The size of the aggregates was about 60nm and they grew as the reaction continued.From the results of energy dispersive X-ray (EDX)spectroscopy analysis and kinetics modeling using the Johnson-Mehl-Avrami (JMA)equation,the diffusion nucleation of Ba 2+ion was found to be dominant during the early stages of aggregation formation.The growth process of “diffusion nucleation -orientation attachment ”revealed the formation mechanism of barium titanate nanoparticle aggregations.Key Words:Barium titanate;

JMA equation;

Hydrothermal method;

Diffusion mechanism;

Orientation attachment

doi:10.3866/PKU.WHXB20112927

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