双掺杂的Sm_(0.9)Sr_(0.1)Al_(1-x)Co_xO_(3-δ)钙钛矿结构导电陶瓷的制备及其电性能  

Preparation and electrical properties of double-doped perovskite structured conducting ceramics Sm_(0.9)Sr_(0.1)Al_(1-x)Co_xO_(3-δ)

作　　者：向军[1] 郭银涛[1] 褚艳秋[1] 周广振[1] 

机构地区：[1]江苏科技大学数理学院,镇江212003

出　　处：《物理学报》2011年第2期602-607,共6页Acta Physica Sinica

基　　金：江苏省高校自然科学研究计划(批准号:2008SL061J)资助的课题~~

摘　　要：采用有机凝胶法结合高温烧结制备了Sm0.9Sr0.1Al1-xCoxO3-δ(SSAC,x=0.2,0.4,0.5,0.6)系列钙钛矿结构混合导电陶瓷,并详细讨论了烧结温度和Co掺杂量对其晶体结构、相组成和电性能的影响.X射线衍射结果显示,过高的烧结温度或Co掺杂量都会导致杂相Sm(Sr)CoO3生成,Co在该体系的固溶限位于50mol%—60mol%之间,Co对Al的部分取代使晶格体积增大.电性能测量结果表明,SSAC陶瓷的电导率主要取决于p型电导,其导电行为符合小极化子跳跃导电机制;随着烧结温度的升高,材料的电导率逐渐增大;在固溶限内随Co含量的增加,SSAC陶瓷的电导率增大,表观活化能减小;1200℃烧结10h制得的单相Sm0.9Sr0.1Al0.5Co0.5O3-δ陶瓷体在800℃的电导率达63.4S/cm,表观活化能为0.14eV.具有良好电性能的SSAC导电陶瓷有望应用于高温电化学领域.A series of new mixed-conducting ceramics Sm0. 9Sr0. 1Al1-xCoxO3-δ（SSAC,x = 0. 2,0. 4,0. 5,0. 6） with perovskite structure were prepared by sintering the precursor powders derived from organic gel process. The effects of sintering temperature and Co doping concentration on the crystal structure,phase composition and electrical properties were also discussed in detail. The X-ray diffraction results show that the over-high sintering temperature or Co doping content will lead to the formation of impure phase with a chemical formula of Sm（Sr）CoO3 in sinters,and the solid solubility limit of Co in this system lies in the range of 50 mol% —60 mol% . The partial substitution of Co for Al in Sm0. 9Sr0. 1Al1-xCoxO3-δ results in an increase in lattice volume. The measurement results of electrical properties reveal that the conductivities of SSAC ceramics are dominated by p-type conduction,and the conduction behavior conforms to the small polaron hopping transport mechanism. With the increasing sintering temperature,the conductivities of as-prepared samples gradually increase. For the SSAC ceramics with Co content lower than the solid solubility limit, it is observed that their conductivities increase with the increase of Co content while the corresponding apparent activation energies decrease. The prepared single-phase Sm0. 9Sr0. 1Al0. 5Co0. 5O3-δ ceramic body by sintering at 1200 ℃ for 10 h has a conductivity of 63. 4 S / cm and an apparent activation energy of 0. 14 eV. These novel SSAC mixed-conducting ceramics with good electrical properties can potentially be used in the field of high temperature electrochemistry.

关 键 词：导电陶瓷 Sr和Co掺杂的SmAlO3 有机凝胶法 电性能 

分 类 号：TQ174.1[化学工程—陶瓷工业]