Nucleation and growth kinetics of La0.7Sr0.3Cr0.4Mn0.6O3-δ SOFC perovskite:Symmetry alteration evolution induced by Cu2+ and Ni2+ impregnation

作     者：A.Concha-Balderrama G.Rojas-George J.Alvarado-Flores H.Esparza-Ponce M.H.Bocanegra-Bernal A.Reyes-Rojas 

作者机构：Centro de Investigación en Materiales Avanzados S.C.(CIMAV)Laboratorio Nacional de NanotecnologíaMiguel de Cervantes 120 Complejo Industrial ChihuahuaCd.de Chihuahua 

出 版 物：《Progress in Natural Science:Materials International》 (自然科学进展·国际材料(英文))

年 卷 期：2016年第26卷第6期

页      面：665-670页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 070301[理学-无机化学] 0702[理学-物理学] 

基　　金：The authors would like to thank Carlos Ornelas  and Pedro Piza for their valuable participation in this work 

主　　题：Perovskite structure Sol-gel method Composite Kinetics Rietveld 

摘      要：La0.7Sr0.3Cr0.4Mn0.6O3-δperovskite nanoparticles have been synthetized using an ethylene glycol modified solgel method and impregnated by Cu0.75Ni0.25nanoparticles. The phase transitions and nucleation kinetics were studied by time resolved x-ray diffraction, Rietveld, Raman spectroscopy and high resolution transmission electron microscopy. Findings have shown that, an atomic disorder dominates from room temperature to 400 °C. Nanoparticles with crystal size 26 nm start through nuclei formation of La0.7Sr0.3Cr0.4Mn0.6O3-δand SrCrO4solid solutions with Pm3m cubic and P21/n monoclinic symmetry respectively in the range of 600–650 °C. Symmetry reduction from the Pm3m→R3c space group had been obtained at a lower temperature（750 °C） than those reported in the literature in oxygen atmosphere and it was confirmed by an octahedral distortion, which takes place in the crystallographic direction[221]/（122）. The Johnson-Mehl-Avrami model had described the whole process, where the existence of two phases was shown before it reached its complete D3d6point group symmetry.