Thermopower of misfit-layered calcium cobaltites

Research output: Chapter in Book/Report/Conference proceedingChapter


Good thermoelectric materials require a large thermopower (S) for generating largethermal voltage, a low electrical resistivity (ρ) for minimizing Joule heating, and a lowthermal conductivity (κ) for retaining the heat at the junctions to obtain a high figure ofmerit Z = S2/ρκ. The calcium cobaltites Ca3Co4O9+δ show large thermopower and lowthermal conductivity and are considered to be a good candidate material forthermoelectric application in waste heat recovery. The composition of Ca3Co4O9+δ couldbe expressed as [Ca2CoO3][CoO2] b1/b2 with the misfit-layered structure. The misfitlayeredstructure comes from different periodicities along the b axis with b1 referring tothe b-axis length of NaCl type [Ca2CoO3] sublattice and b2 referring to the b-axis lengthof [CoO2] sublattice. Therefore, it can be viewed as being composed of two subsystems,i.e., the distorted NaCl-type [Ca2CoO3] sublattice and the CdI2-type [CoO2] sublatticealternatively stacking along the c axis. This chapter presents the data and discussion forthe thermopower of a series of misfit-layered oxides Ca3Co4O9+δ where either the Co siteis partially substituted by transition metals or the Ca site is partially substituted by rareearth metals.

Original languageEnglish
Title of host publicationThermoelectric Power
PublisherNova Science Publishers, Inc.
Number of pages36
ISBN (Print)9781611221923
Publication statusPublished - 2011 Dec 1

All Science Journal Classification (ASJC) codes

  • Energy(all)

Fingerprint Dive into the research topics of 'Thermopower of misfit-layered calcium cobaltites'. Together they form a unique fingerprint.

Cite this