High Temperature Thermoelectric Properties of Y and Fe codopants in Ca3Co4O9+δ

NingYu Wu, Ngo Van Nong, Nini Pryds, Søren Linderoth

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Abstract

A series of Ca3xYx Co4yFeyO9+δ powders was synthesized by auto-combustion reaction and densified with spark plasma sintering (SPS) processing. The electrical resistivity and the Seebeck coefficient increase with the increasing yttrium content, while the electrical resistivity decreases with the iron content below 0.05. The reasons for the increase in both the electrical resistivity and the Seebeck coefficient with the yttrium substitution are due to the carrier (Co4+) number reduction in CdI2 type CoO2 layer. In contrary, iron substitution below certain content may only occur in rocksalt type Ca2CoO3 layer resulting in the increase of the carrier number. The Y and Fe co-dopants effect on the thermal conductivity is not significant even though the yttrium heavier atomic weight is expected as an effective phonon scattering site. At 800 °C, the improved power factor of 520 μW/m•K2 from x=0.2 and y=0.03 sample was obtained, compared with the power factor of 450 μW/m•K2 from pure Ca3Co4O9+δ, which demonstrates the improvement of Ca3Co4O9+δ thermoelectric properties with co-dopants yttrium and iron.
Original languageEnglish
Publication date2013
Publication statusPublished - 2013
Event11th European Conference on Thermoelectrics (ECT 2013) - Noordwijk, Netherlands
Duration: 18 Nov 201320 Nov 2013

Conference

Conference11th European Conference on Thermoelectrics (ECT 2013)
CountryNetherlands
CityNoordwijk
Period18/11/201320/11/2013

Cite this

Wu, N., Van Nong, N., Pryds, N., & Linderoth, S. (2013). High Temperature Thermoelectric Properties of Y and Fe codopants in Ca3Co4O9+δ. Abstract from 11th European Conference on Thermoelectrics (ECT 2013), Noordwijk, Netherlands.