微波法合成纳米BaTi03及其表征

以TiCl4和BaCl2为主要原料，用微波法一步成功合成纳米BaTiO3，采用X射线衍射谱（XRD）、扫描电镜（SEM）、漫反射吸收谱（DRS）、介电常数谱和热重一差热分析（TG-DTA）表征，XRD和SEM分析表明，合成的BaTiO3为纯的立方相纳米BaTiO3，颗粒大小均匀，分散性好，晶粒粒径在90nm左右；DRS和介电常数测试表明，纳米BaTiO3禁带宽度为3．4eV，具有良好的介电性能；TG-DTA和XRD测试表明，在400℃以前，纳米BaTiO3表面吸附的残余有机物质燃烧放热，有l-4％左右的热失重，对应在290℃左右有较强的放热峰；1000℃煅烧后才有部分立方相的BaTiO3转化成了四方相的BaTiO3，纳米BaTi03表现出了良好的热稳定性。

Characterization and Preparation of Nanoparticulate BaTi03 by Microwave Process

Taking TIC14 and BaC12 as main raw material, the BaTiO3 nanoparticles were synthesized by microwave process. The BaTiO3 nanopartieles were characterized by powder X-ray diffraction （XRD） , scanning electron microscopy （SEM） , UV- visible diffuse reflectance spectroscopy （DRS） , dielectric constant spectrum, thermogravimetry and differential thermal analysis （TG-DTA） . The results of XRD and SEM showed that BaTiO3 was pure cubic crystal phase, and the particle＇s size was nearly 90 nm, owned uniform and good dispersion. It was found that the BaTiO3 nanoparticles showed excellent dielectric properties and band gap of 3.4 eV by DRS and dielectric constant spectrum. The TG and DTA curves reflected the thermal decomposition of organic species and the phase transformation of materials. It could be clearly seen that before 400 ℃, there were residual organic matter adsorbed on the surface of nano BaTiO3 combusted, 1.4% of heat loss was observed, associated with a big exothermic peak at 290 ℃ The portion cubic phase BaTiO3 was transfbrmed into tetragonal BaTiO3 after calcination at 1000℃. The BaTiO3 nanoparticles showed good thermal stability.