【摘要】 以分析纯的硝酸镧、硝酸锶、硝酸钴和硝酸铁为原料,通过柠檬酸法(Citrate)和聚乙烯醇法(PVA)合成了LSCF纳米粉体。采用热重(TG)、差热分析(DTA)、傅立叶红外光谱(FT-IR)、X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)和BET等技术比较研究了两种方法合成LSCF的成胶过程,晶相形成过程和微观形貌等的异同,并比较了它们的制备成本。结果表明,二种方法均在800℃煅烧可得到钙钛矿纯相,成相过程中都有碳酸锶生成。柠檬酸法和聚乙烯醇法所得粉体粒度分别30.8nm和34.2nm;比表面积分别为37.4m2/g和28.2m2/g。聚乙烯醇法的制粉周期较短、合成过程要求没有柠檬酸法严格、制备成本也稍低,因此聚乙烯醇法更适于商业化生产。更多还原

【Abstract】 La0.8Sr0.2Co0.5Fe0.5O3 (LSCF) nanocrystals were prepared by citrate method and Polyvinyl alcohol(PVA) method respectively, using water solutions of lanthanum(La3+), Strontium(Sr2+), cobalt(Co3+) and iron(Fe3+) nitrates aqueous solution as raw materials. Differential thermal analysis (DTA), Thermogravimetric analysis (TG), Infrared spectra (IR), X-ray powder diffraction (XRD), Scanning electron microscopy (SEM) , and BET were used to characterize these nanoparticles and their phase formation processes. It was found that pure perrovskite phase can be attained at 800℃ for both gels progresses with a mean size of nanameter grade. Compared with the citrate methods, Polyvinyl alcohol methods can produce nanopowder in a shorter period with the same purity and stoichiometric control. Nevertheless, this means of production is cheaper and much faster than the ones commonly used to produce La0.8Sr0.2Co1-yFeyO3 (LSCF) by conventional citrate sol-gel techniques.更多还原