采用溶剂热法一步合成了3~5nm单分散纳米晶钛酸钡(BaTiO3)粉体,利用原位变温Raman光谱研究了纳米晶BaTiO3粉体的微区结构特性。结果表明:纳米晶BaTiO3相变区间弥散,呈现多相共存的结构特性;即使晶粒尺寸小到5nm,仍然具有与大晶粒BaTiO3陶瓷类似的行为,即随温度升高经历从三方相→正交相→四方相→立方相的连续相变。 Single-phase nanocrystalline barium titanate (BaTiO3) powders of 3 ~ 5 nm were synthesized by solvothermal method. The in-situ temperature-programmed Raman spectroscopy was used to study the microstructure of nanocrystalline BaTiO3 powders. The results show that the phase transition of BaTiO3 nanocrystals disperse and exhibit heterogeneous coexistence of structural features. The grain size of BaTiO3 ceramics is similar to that of the large grain BaTiO3 ceramics even with the grain size as small as 5 nm, ie, Cross-phase → tetragonal phase → cubic phase of the continuous phase change.