Influence of the calcination procedure on the thermoelectric properties of calcium cobaltite Ca₃Co₄O₉

Title data

Bresch, Sophie ; Mieller, Bjoern ; Selleng, Christian ; Stöcker, Thomas ; Moos, Ralf ; Rabe, Torsten:
Influence of the calcination procedure on the thermoelectric properties of calcium cobaltite Ca₃Co₄O₉.
In: Journal of Electroceramics. Vol. 40 (2018) Issue 3 . - pp. 225-234.
ISSN 1573-8663
DOI: https://doi.org/10.1007/s10832-018-0124-3

Official URL:

Abstract in another language

Calcium cobaltite is one of the most promising oxide p-type thermoelectric materials. The solid-state reaction (or calcination, respectively), which is well known for large-scale powder synthesis of functional materials, can also be used for the synthesis of thermoelectric oxides. There are various calcination routines in literature for Ca3Co4O9 powder synthesis, but no systematic study has been done on the influence of calcination procedure on thermoelectric properties. Therefore, the influence of calcination conditions on the Seebeck coefficient and the electrical conductivity was studied by modifying calcination temperature, dwell time, particle size of raw materials and number of calcination cycles. This study shows that elevated temperatures, longer dwell times, or repeated calcinations during powder synthesis do not improve but deteriorate the thermoelectric properties of calcium cobaltite. Diffusion during calcination leads to idiomorphic grain growth, which lowers the driving force for sintering of the calcined powder. A lower driving force for sintering reduces the densification. The electrical conductivity increases linearly with densification. The calcination procedure barely influences the Seebeck coefficient. The calcination procedure has no influence on the phase formation of the sintered specimens.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Engineering Science Faculties > Faculty of Engineering Science > Chair Functional Materials > Chair Functional Materials - Univ.-Prof. Dr.-Ing. Ralf Moos Profile Fields > Advanced Fields > Advanced Materials Research Institutions > Central research institutes > Bayreuth Center for Material Science and Engineering - BayMAT Faculties Faculties > Faculty of Engineering Science > Chair Functional Materials Profile Fields Profile Fields > Advanced Fields Research Institutions Research Institutions > Central research institutes
Result of work at the UBT:	Yes
DDC Subjects:	600 Technology, medicine, applied sciences > 620 Engineering
Date Deposited:	23 Jul 2018 06:48
Last Modified:	14 Mar 2024 14:37
URI:	https://eref.uni-bayreuth.de/id/eprint/45152