摘要
采用溶胶-凝胶法(sol-gel)合成了一系列复杂的稀上锆酸盐陶瓷粉体,(La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_2O_7、(La_(0.4)Sm_(0.5)Yb_(0.1))_2(Zr_(0.7)Ce_(0.3)O_7、((La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_(0.7)Ce_(0.4))_2O_(7.4)和(La_(0.4)Sm_(0.5)Yb_(0.1))_2(Zr_(0.7)Ce_(0.3)0_7 3。利用X射线衍射(XRD)仪及场发射扫描电镜(SEM)对各粉体和块体的微观结构进行了表征,采用阻抗分析仪测试了各陶瓷的介电性能。结果表明,复杂稀土锆酸盐均具有单一的焦绿石结构,其介电常数几乎与频率无关,并随Ce^(4+)含量的增加而逐渐降低,但当A位掺入Sr^(2+)时,材料的介电常数增大:同时,焦绿石结构材料的介电常数随r(A^(3+))/rB^(4+))值的增大而上升,这可能与结构中氧空位的有序程度有关。
Complex rare-earth zirconates(La_(0.4)Sm_(0.5)Yb_(0.1))_2Zr_2O_7,(La_(0.4)Sm_(0.5)Yb_(0.1)_2(Zr_(0.7)Ce_(0.3))_2O_7,(La_(0.4)Sm_(0.5)Yb_(0.1))_2(Zr_(0.7)Ce_(0.4))_2O_(7.4)and(Sr_(0.1)La_(0.3)Sm_(0.5)Yb_(0.1))_2(Zr_(0.7)Ce_(0.4))_2O__(7.3) powders were synthesized by sol-gel method.The phase structure,microstructures and the dielectric properties were investigated.XRD and SEM results revealed that the complex rare-earth zirconates with single pyrochlore structure were prepared and no other phases existed among the grains.Intermediate dielectric constants and low dielectric loss were examined.The dielectric constants were found to be nearly frequency independent.With Ce^(4+) content increasing,the dielectric constant of the zirconates decreased,while Sr^(2+) substituted at site A increased the dielectric constant.The dielectric constant values increase with increasing the r(A^(3+))/r(B^(4+)) value in the pyrochlore-type phase region,which can be explained by the increase in the degree of ordering of oxygen vacancy.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2012年第S3期483-486,共4页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China(51102016)
Commission of Science Technology and Industry for National Defense(9140A12020306BQ0102)
关键词
复杂稀上锆酸盐
介电性能
热障涂层
SOL-GEL
complex rare-earth zirconates
dielectric properties
thermal barrier coatings
sol-gel
