Lot of studies are devoted to the properties of perovskite type solid solutions, with formula LaMeO3, Me-transition metal. The oxides based on rare earth and 3d transition elements were found to be promising materials for use as electrodes, catalysts or membranes. Investigations are carried out to find appropriate compositions with the best necessary properties. Here we report the preparation and characterization of LaMeO3 perovskite-type oxides in the series of lanthanum manganate LaMnO3 and cobaltite LaCoO3. It is neccessary to prepare high quality powders with controlled stoichiometry and microstructure, therefore an important feature of our investigation is the preparation method. The powders are obtained by a simple technique as the polymerizable complex method based on the Pechini-type reaction route. A mixed solution of citric acid (CA) and ethylene glycol (EG) with La and Mn or Co ions is polymerized. The CA-metal complexes can be polymerized by EG, as the polymerization reaction induced by EG greatly inhibits cation segregation. An important purpose is the reaction chemistry of the polymerized complex route for the LaMnO3 and LaCoO3 synthesis, a key issue being to control the complex formation and polymerization in La-Mn and La-Co solutions and the crystallization behaviour of solid precursors at different heat treatments. The structure of the obtained compounds is investigated by X-ray diffraction (XRD). The microstructure and the grain size distribution are investigated by scanning electron microscopy (SEM); BET method is used for the determination of the specific surface area. Very fine, homogenous, narrow grain size distribution of particles were obtained after only treatment for 6 hours at temperature as low as 600°C for LaCoO3 and 700°C for LaMnO3.
|ジャーナル||Key Engineering Materials|
|出版ステータス||Published - 2001 1 1|
|イベント||7th Conference and Exhibition of the European Ceramic Society - Brugge, Belgium|
継続期間: 2001 9 9 → 2001 9 13
ASJC Scopus subject areas