Y_(1-x)Ca_xBaCo_2O_(5+δ)的制备和性能表征  

Fabrication and Characterization of Y_(1-x)Ca_xBaCo_2O_(5+δ)

作　　者：张亚梅[1] 吴小山[2] 刘家欢[1] 韩汝取[1] 

机构地区：[1]江苏科技大学物理系,镇江212003 [2]南京大学固体微结构国家重点实验室,南京210093

出　　处：《无机化学学报》2011年第12期2362-2366,共5页Chinese Journal of Inorganic Chemistry

基　　金：江苏科技大学博士科研启动基金;江苏科技大学校管基金(No.2009SL153J)资助项目

摘　　要：利用固相反应法合成了层状钙钛矿钴氧化物Y1-xCaxBaCo2O5+δ(x=0,0.1,0.15,0.2)材料,系统研究了材料的氧吸附性能和电输运性质。XRD结果表明Ca2+掺杂的样品具有母相YBaCo2O5+δ层状钙钛矿结构,随着Ca2+掺杂量的增加,样品的晶格参数增大。TG结果显示:从室温到1 273 K,所有样品经历了两次吸氧和脱氧的过程,Ca2+掺杂增强了样品的氧脱附性能。在中低温下,约650 K附近,吸氧量达到最大,同时,样品发生了半导体金属转变。Ca2+掺杂量的增加,半导体金属转变温度增大,电导率下降。半导体金属转变与氧变化量δ有关而电导率下降与Ca2+掺杂引起Co3+离子的增加有关。Layered perovskite cobalt oxide Y1-xCaxBaCo2O5＋δ（x=0,0.1,0.15,0.2） materials were synthesized by solid state reaction.Oxygen absorption and electrical transport properties of all the samples have been investigated.XRD results indicate that the structure of Ca2＋ doped samples has the same Layered perovskite structure of parent phase YBaCo2O5＋δ and their lattice constants increase with Ca2＋ doping content increase.TG results present that all the samples experience two oxygen absorption and desorption processes from room temperature to 1 273 K and Ca2＋ doping can enhance oxygen desorption property.At medium and low temperature（about 650 K）,all the samples have the maximal oxygen absorption capability and have the semiconductor-metal transition at the same time.The increase of Ca2＋ doping content increases the semiconductor-metal transition temperature and depresses the conductivity.It is argued that the semiconductor-metal transition is related to the oxygen variance δ and while the depression of conductivity is related to the increasing of Co3＋ induced by Ca2＋ doping.

关 键 词：层状钙钛矿 半导体金属转变 氧吸附 电导率 

分 类 号：O469[理学—凝聚态物理]