摘要
采用尿素-硝酸盐法制备了Sm0.5Sr0.5Co1-xCuxO3-δ（x=0~0.5）阴极材料。用TG-DSC,SEM,XRD和热膨胀仪对材料的形成过程、晶体结构、烧结体的微观结构及热膨胀性能进行了表征。用直流四端子法测试材料在500~800℃范围内的电导率。结果表明,制备样品的主晶相为正交钙钛矿结构,体系含有杂相;电导率随温度和Cu含量的变化关系表现为,x≤0.2时的样品随温度升高电导率降低,x≥0.3时随温度升高电导率增大,组成为x=0.2的样品电导率最高,500℃达到703.1 S.cm-1。材料的热膨胀系数随掺杂的Cu含量增加而降低。
The Sm0.5Sr0.5Co1-xCuxO3-δ powders were synthesized by a urea-nitrate combustion method.The formation process,crystal structure,micrograph and thermal expansion coefficient（TEC） of the as-synthesized samples were investigated by TG-DSC,XRD,SEM and dilatometer,respectively.The electrical conductivities of the samples were measured by four point electrodes method at 500~800 ℃ in air.The results showed that the major phase of the as-synthesized powders was orthorhombic perovskite structure,whereas some impurity peaks existed in the samples.The conductivity of the samples with x≤0.2 decreased with increasing temperature,while for the samples with x≥0.3,the electrical conductivity increased with temperature.The sample with x=0.2 exhibited the highest conductivity,which was 703.1 S·cm-1 at 500 ℃.The thermal expansion coefficients of Sm0.5Sr0.5Co1-xCuxO3-δ were decreased monotonously with Cu doping.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2010年第6期716-720,共5页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金(50872049)资助
