High temperature transport and thermoelectric properties of Ca3−xErxCo4O9+δ

✍ Scribed by J. Pei; G. Chen; N. Zhou; D.Q. Lu; F. Xiao

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 742 KB
• Volume: 406
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2010.11.043

✦ Synopsis

Ca 3 À x Er x Co 4 O 9 + d (x ¼ 0, 0.05, 0.15, 0.3 and 0.5) samples were prepared using a sol-gel method followed by hot-pressing sintering technique. Powder X-ray diffraction analysis showed the single-phases of Ca 3 À x Er x Co 4 O 9 + d were obtained up to x ¼ 0.3 and the crystallinity of the samples decreased with increasing Er-doping amount. The high-temperature (323-1073 K) thermoelectric properties of the samples were investigated. The substitution of Er 3 + for Ca 2 + resulted in the decrease of electrical conductivity, thermal conductivity and the increase of Seebeck coefficient for all the samples except the x ¼ 0.05 one. The dimensionless figure of merit ZT reached 0.28 at 1073 K for Ca 2.7 Er 0.3 Co 4 O 9 + d , indicating the thermoelectric properties of CaCo 4 O 9 + d can be enhanced by doping Er in the system.