Effects of oxygen defects on structure and properties of Sm_(0.5)Sr_(0.5)CoO_(3-δ) annealed in different atmospheres  

作　　者：陆依 陈乐 陆春华 倪亚茹 许仲梓 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering,College of Materials Science and Engineering,Nanjing University of Technology

出　　处：《Journal of Rare Earths》2013年第12期1183-1190,共8页稀土学报（英文版）

基　　金：supported by Innovation Scholars "Climbing" Program of Jiangsu Province(SBK200910148);the Innovation Foundation for Graduate Students of Jiangsu Province(CXZZ13_0425);the Priority Academic Program Development of Jiangsu Higher Edu-cation Institutions(PAPD)

摘　　要：Samples of Sm0.5Sr0.5CoO3–δ were annealed in different atmospheres（Ar,N2,and O2） and temperatures（400 1200 oC）,and changes in their masses,structures,surface transport properties,optical properties,and oxygen nonstoichiometries were investigated using thermogravimetric（TG） analyses,X-ray diffraction（XRD） analyses,electrical conductivity measurements,reflection spectra measurements,and X-ray photoelectron spectroscopy,respectively.The TG analyses,performed in air and an N2 atmosphere,allowed us to determine the changes in the masses of the samples.The results of the XRD analyses elucidated the changes in the structure of the samples under different conditions.The XPS spectra and simulation data indicated that the number of oxygen defects generated in the samples depended on the temperature and atmosphere.At high temperatures,the surface conductivities and full-spectrum reflectivities of the samples decreased with an increase in the number of oxygen vacancies.In an oxidative atmosphere,the samples exhibited outstanding visible and near-infrared light absorption.Furthermore,the samples were highly sensitive to a reducing atmosphere at various temperatures.On the basis of the fact that the properties of Sm0.5Sr0.5CoO3–δ vary with the environment,it has potential use in high-temperature applications such as weather sensors.Samples of Sm0.5Sr0.5CoO3–δ were annealed in different atmospheres（Ar,N2,and O2） and temperatures（400 1200 oC）,and changes in their masses,structures,surface transport properties,optical properties,and oxygen nonstoichiometries were investigated using thermogravimetric（TG） analyses,X-ray diffraction（XRD） analyses,electrical conductivity measurements,reflection spectra measurements,and X-ray photoelectron spectroscopy,respectively.The TG analyses,performed in air and an N2 atmosphere,allowed us to determine the changes in the masses of the samples.The results of the XRD analyses elucidated the changes in the structure of the samples under different conditions.The XPS spectra and simulation data indicated that the number of oxygen defects generated in the samples depended on the temperature and atmosphere.At high temperatures,the surface conductivities and full-spectrum reflectivities of the samples decreased with an increase in the number of oxygen vacancies.In an oxidative atmosphere,the samples exhibited outstanding visible and near-infrared light absorption.Furthermore,the samples were highly sensitive to a reducing atmosphere at various temperatures.On the basis of the fact that the properties of Sm0.5Sr0.5CoO3–δ vary with the environment,it has potential use in high-temperature applications such as weather sensors.

关 键 词：CONDUCTIVITY optical properties reflectance XPS oxygen vacancies rare earths 

分 类 号：O611.3[理学—无机化学]