采用醇/水混合溶剂方法制备了不同粒径的纳米BaF2粉体,研究了粉体的热稳定性.结果表明,纳米BaF2粉体的粒径随着混合溶剂中乙醇含量的提高而减小,粉体的形貌和分散性也都随之改变.根据在不同升温速率下测量的每种粒径纳米BaF2粉体的DSC曲线,由Kissinger方程求出了各晶粒长大激活能,BaF2晶粒长大激活能随着粉体粒径的减小而线性地减小,纳米晶BaF2的热稳定性随着粒径的减小而降低.
BaF2 nanocrystalline powders with different particle sizes were synthesized by precipitation in the ethanol-water mixed solvents, and the thermal stability of powders was investigated. The results showed that the size of BaF2 powders decreases with increasing the volume ratio of ethanol to water of mixed solvents, and both the morphology and dispersion also modified. The DSC curves of nanocrystalline BaF2 powders were measured at different heating rates. According to the Kissinger equation, the activation energy for grain growth of nanocrystalline BaF2 powders were calculated. It was shown that the activation energy decreased linearly with the decrease of particle size of nanocrystalline BaF2 powders, which means the thermal stability decreases with the particle size decreasing.