钙钛矿氧化物Sm_(1-x)Sr_xCoO_(3-δ)的非化学计量氧含量测定方法比较  

Comparison of Methods in Determining Non-stoichiometric Oxygen Content of Perovskite Sm_(1-x)Sr_xCoO_(3-δ)

作　　者：陆依[1] 陈乐[1] 陆春华[1] 倪亚茹[1] 许仲梓[1] 

机构地区：[1]南京工业大学材料化学工程国家重点实验室,南京210009

出　　处：《材料导报》2013年第8期105-108,116,共5页Materials Reports

基　　金：江苏省研究生培养创新工程(CXZZ11_0329);江苏省创新学者攀登项目(SBK200910148);江苏省自然科学基金(BK2010553)

摘　　要：采用碘定量滴定和X射线能谱分析对钙钛矿氧化物Sm1-xSrxCoO3-δ(x=0.2,0.3,0.5,0.7,0.8)体系进行了非化学计量氧含量的测定。研究表明,两种测试结果变化趋势一致,各有优劣。采用直流四探针法研究了氧空位浓度与导电性能的关系,结果表明,随着Sr掺量的增加,Sm1-xSrxCoO3-δ氧空位浓度增加,在x=0.5时导电性最佳,原因是氧空位浓度过高会导致空位团簇,减少有效空位,影响电子-离子的传导。Iodometry titration and Xray spectroscopy analysis were applied to investigate the non-stoichiome- tric oxygen content of Sm1-xSrxCoO3-δ（x=0. 2, 0. 3,0. 5,0.7,0. 8）. The results indicate that these two methods ex- hibit their own superiority, and present the same trend. The relationship between oxygen vacancy concentration and electrical conductivity was studied by a four-probe DC method. The results show that with the increasing of Sr con- tent, the oxygen vacancies increased, and Sn0. 5 Sr0.5 CoO3-δ displayed the best electrical conductivity performance. High oxygen vacancies concentration leads to vacancy clusters, thus reducing the effective vacancies and influencing the transmission of electrons and ions.

关 键 词：钙钛矿 非化学计量氧 碘定量滴定 X射线能谱分析 电导率 

分 类 号：TQ132[化学工程—无机化工] TQ133