Environmentally friendly synthesis methods to obtain the misfit [Ca2CoO3-delta](0.62)[CoO2] thermoelectric material

authors	Emerenciano, AA; Araujo, AJM; Grilo, JPF; Macedo, DA; Rasekh, S; Kovalevsky, AV; Paskocimas, CA; Nascimento, RM
nationality	International
journal	MATERIALS LETTERS
author keywords	Ca3Co4O9; Ceramics; Environmentally friendly precursors; Proteic sol-gel synthesis; Electrical properties
keywords	CA3CO4O9 CERAMICS; COBALT OXIDE; MICROSTRUCTURE; ENHANCEMENT; PERFORMANCE; CA; BEHAVIOR; C349
abstract	This work reports the microstructural and thermoelectric characterization of the misfit [Ca2CoO3-delta](0.62)[CoO2] compound obtained by a solid-state synthesis using mollusk shells and a proteic sol-gel method, which uses gelatin as a polymerizing agent. The results clearly demonstrate the capability of these routes to produce pure Ca3Co4O9 with plate-like morphology. Sintered ceramic samples show randomly oriented grains and relative densities in the range of 63-67%. The obtained microstructures provide reasonable electrical properties and result in competitive thermoelectric performance for the material prepared by the proteic sol-gel synthesis (P.F. of 205 mu W/K-2 m at 700 degrees C). (C) 2019 Elsevier B.V. All rights reserved.
publisher	ELSEVIER
issn	0167-577X
isbn	1873-4979
year published	2019
volume	254
beginning page	286
ending page	289
digital object identifier (doi)	10.1016/j.matlet.2019.07.053
web of science category	Materials Science, Multidisciplinary; Physics, Applied
subject category	Materials Science; Physics
unique article identifier	WOS:000484824500072