纳米LaF_3块体的制备及其热稳定性研究  

The Study on Preparation and Thermal Stability of Nanocrystalline LaF_3 Bulk Material

作　　者：吴大雄[1] 吴希俊[1] 吕燕飞[1] 王晖[1] 

机构地区：[1]浙江大学,浙江杭州310027

出　　处：《稀有金属材料与工程》2006年第8期1247-1250,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(59872031)

摘　　要：采用水溶液沉淀法成功制备了晶粒尺寸约为16.7nm的纳米LaF3粉体。采用真空(10-4Pa)压结法(1GPa)制成纳米LaF3块体。用XRD分析测试了不同退火温度下纳米LaF3块体的晶粒尺寸。结果表明,随着退火温度的升高,纳米LaF3块体的晶粒尺寸增大,从原始晶粒尺寸l6.7nm长大到900℃时的92.6nm。同时在不同升温速率下测量纳米LaF3块体的DSC曲线,并由Kissinger方程求得其晶粒长大激活能为2.01eV。Nanocrystalline powder of LaF3 with an average grain size of 16.7 nm was synthesized by a method of direct precipitation from water solution. Nano-LaF3 bulk material was prepared by compacting the powder to 1 GPa at room temperature and a vacuum of 10^-4Pa. The grain size of the nano-LaF3 bulk material annealed at various temperatures was measured by X-ray diffraction. The results indicated a grain size increase from 16.7 nm to 92.6 nm when the annealing temperature rose to 900 ℃. The DSC curves ofnano-LaF3 bulk material were measured at heating rates of 5 K / min, 1 0 K / rain, 1 5 K / min and 20 K / min, respectively. According to the Kissinger equation, the activation energy for grain growth ofnano-LaF3 bulk material was calculated to be 2.01 eV or 233 kJ / mol.

关 键 词：纳米LaF3块体 热稳定性 晶粒长大激活能 晶粒尺寸 

分 类 号：TB383.1[一般工业技术—材料科学与工程]