Thermoelectric properties of sol–gel derived cobaltite Bi2Ca2.4Co2Oy

✍ Scribed by L.H. Yin; R. Ang; L.J. Li; B.C. Zhao; Y.K. Fu; X.B. Zhu; Z.R. Yang; W.H. Song; Y.P. Sun

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 627 KB
• Volume: 406
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2011.04.066

✦ Synopsis

Layered misfit cobaltite Bi 2 Ca 2.4 Co 2 O y has been synthesized by a sol-gel method. This compound exhibits large thermoelectric (TE) power (S 300 K $ 170 mV K À 1 ), low resistivity (r 300 K $ 42 mO cm) and relatively small thermal conductivity (k 300 K $ 2.8 W K À 1 m À 1 ) at room temperature. Furthermore, the resistivity of this compound displays a metallic behavior above T * $ 150 K with a semiconducting behavior below this temperature. This abnormal behavior in resistivity is analogous to those observed in Sr and Ba based misfit cobaltites. The observed features of the TE have been discussed based on the narrow band model.