锶掺杂对La_(1-x)Sr_xNbO_(4-σ)质子导体性能的影响  

Investigation on Effect of Sr Doping on Properties of Protonic Conductor La_(1-x)Sr_xNbO_(4-σ)

作　　者：王岭[1] 杨学宾[1] 周会珠[1] 李跃华[1] 戴磊[1] 

机构地区：[1]河北联合大学化学工程学院,唐山063009

出　　处：《无机化学学报》2014年第2期310-316,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.50772030;50972038;51272067);河北省自然基金(No.E2011209036;E2012209018)资助项目

摘　　要：利用高温固相反应法制备了Sr掺杂LaNbO4质子导体La1-xSrxNbO4-σ(0≤x≤0.02),并且对其性能进行了表征。XRD分析表明,所有的样品具有单斜结构,晶胞体积随Sr掺杂量的增加而增大;La1-xSrxNbO4-σ样品在沸水中和二氧化碳气氛中具有很好的化学稳定性。SEM分析表明,La1-x Srx NbO4-σ粉体经1 500℃烧结8 h后均得到致密的、晶粒均匀的样品;Sr的掺杂抑制了陶瓷体裂缝的产生和晶粒的过度增长;随Sr的掺杂量增加,晶粒变小。交流阻抗谱分析表明,Sr掺杂改变了LaNbO4的电导率,其中样品La0.995Sr0.005NbO4-σ具有最高的电导率;样品在25℃水汽饱和的5%H2-Ar气氛下的电导率明显高于干燥空气气氛,在800℃时,La0.995Sr0.005NbO4-σ电导率达到0.003 S·cm-1,电导活化能为0.44 eV。The proton conductors La1-xSrxNbO4-σ （0≤x≤0.02） are synthesized by solid-state reaction and their properties are characterized. XRDanalysis shows that all composition samples are monoclinic structure; with an increase in Sr doped amount, cell volume becomes big; La1-xSrxNbO4-σ samples display excellent chemical stability in boiling water and carbon dioxide atmosphere. SEManalysis shows that after the La1-xSrxNbO4-σ powders are sintered at 1500 ℃ for 8 h in air, dense samples with uniform crystalline size are obtained; The Sr doping inhibits crack formation and excessive growth of crystal grain; with an increase in Sr doped amount, crystal grain size becomes small. ACimpedance spectroscopy analysis indicates that conductivities of LaNbO4 are changed by Sr doping and among all samples, La0.995Sr0.005NbO4-σ is of the highest conductivity; the conductivities of the La1-xSrxNbO4-σ samples in humid 5% H2-Ar atmosphere are much higher than that those in dry air; conductivity of La0.995Sr0.005NbO4-σ is 0.003 S·cm-1 in humid 5% H2-Ar atmosphere at 800 ℃ and its conducting activation energy is 0.44 eV.

关 键 词：LaNbO4 Sr掺杂 质子导体 电导率 化学稳定性 

分 类 号：TQ13[化学工程—无机化工]