(鋼鐵研究總院 功能材料研究所，北京 100081)
摘 要: 采用CAC法制備具有高度結(jié)晶各向異性的Ni摻雜NaxCoO2熱電氧化物。X射線衍射和場發(fā)射掃描電子顯微鏡測試顯示樣品內(nèi)層狀晶粒的c軸沿著施壓方向取向排列，形成高度織構(gòu)。Ni的摻雜使得樣品晶粒尺寸明顯減小。熱電性質(zhì)的測試表明：Ni的摻雜雖然提高聲子散射，降低熱導(dǎo)率值，但同時也加大載流子散射，提高電阻率。Seebeck系數(shù)有明顯提高，最大值達到154 μV/K，顯示NaxCoO2氧化物熱電材料采用Co位摻雜改進性能的發(fā)展?jié)摿Α?/DIV>
關(guān)鍵字: NaxCoO2；熱電性能；摻雜；Seebeck系數(shù)
（Functional Materials Research Institute, Central Iron and Steel Research Institute, Beijing 100081, China）
Abstract:Ni-substituted NaxCoO2 thermoelectric oxide ceramics with high crystallographic anisotropy were synthesized successfully by citric acid complex (CAC) process. The results of XRD, FE-SEM measurements and thermoelectric properties show that c-axis of layered grain within the sample aligns along the pressing direction and the sample is highly textured. With Ni substitution, the grain size obviously decreases. Ni substitution results in lower thermal conductivity and higher electrical resistivity. On the other hand, Ni substitution leads to the significant increase of Seebeck coefficient, and the maximum value reaches 154 μV/K. The experimental results indicate that the substitution of Co-sites can improve the thermoelectric properties of NaxCoO2.
Key words: NaxCoO2; thermoelectric properties; substitution; Seebeck coefficient
