新型混合导电陶瓷Sm_(0.9)Sr_(0.1)Al_(1-x)Cr_xO_(3-δ)的制备及电性能  

Preparation and Electrical Properties of Novel Sm_(0.9)Sr_(0.1)Al_(1-x)Cr_xO_(3-δ) Mixed Conducting Ceramics

作　　者：向军[1] 郭银涛[1] 周广振[1] 褚艳秋[1] 

机构地区：[1]江苏科技大学数理学院,江苏镇江212003

出　　处：《硅酸盐学报》2011年第12期1934-1940,共7页Journal of The Chinese Ceramic Society

基　　金：江苏省高校自然科学研究计划(2008SL0061J);江苏省青蓝工程及江苏省普通高校研究生创新计划(CXLX11-0293)资助项目

摘　　要：采用有机凝胶法结合后期的高温烧结制备Sm0.9Sr0.1Al1-xCrxO3-δ(SSAC,x=0～0.4)系列氧离子-电子混合导电陶瓷。用热重-差热分析、X射线衍射、扫描电子显微镜和直流四引线法等技术分别表征凝胶前驱体的热分解及相演化过程和烧结体的晶体结构、微观形貌以及电导率。结果显示:凝胶前驱体经900℃焙烧5 h可以形成结晶良好的正交钙钛矿相纳米粉体;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绝热跳跃传输机制;随着烧结温度的升高,Sm0.9Sr0.1Al0.6Cr0.4O3-δ的电导率和相对密度都先增大后减小,1550℃烧结10h的样品具有最高的电导率和相对密度;SSAC陶瓷的电导率以及晶格常数随Cr掺量x的增加呈现出相同的变化规律,即先增大后减小,当x>0.2时又开始变大,而相应的活化能的变化行为则刚好与之相反。A series of Sm 0.9 Sr 0.1 Al 1–x Cr x O 3–δ （SSAC, x = 0–0.4） oxygen anion-electron mixed conducting ceramics were prepared by organic-gel process and subsequent high-temperature sintering. Thermal decomposition and phase evolution processes of gel precur- sors as well as crystal structure, micromorphology and electrical properties of sintered samples were investigated by thermogravimet- ric–differential thermal analysis, X-ray diffraction, scanning electron microscopy, and direct current four-wire technique. Results re- veal that well-crystallized Sm0.9Sr0.1Al1-xCrxO3-δ nanopowders with an orthorhombic perovskite structure can be obtained by calcining the gel precursors at 900 ℃ for 5 h. Conductivities of SSAC ceramics are dominated by p-type conduction and conduction behavior conforms to the adiabatic small polaron hopping transport mechanism. Both electrical conductivity and relative density of Sm0.9Sr0.1Al1-xCrxO3-δ ceramics increase initially and then decrease with increasing sintering temperature, and the sample sintered at 1 550 ℃ for 10 h has the highest electrical conductivity and relative density among all the samples. The conductivities and lattice constants of the SSAC ceramics with different compositions exhibit the same dependence on Cr dosage and their values first increase and then decrease with increasing Cr dosage, and finally begin to increase again as x is more than 0.2, while the dependence of corre- sponding apparent activation energies on Cr dosage is just the opposite.

关 键 词：锶铬掺杂铝酸钐 电性能 烧结温度:掺量 

分 类 号：O611.62[理学—无机化学] O482.4[理学—化学]