Improving bulk Ca3Co4O9 thermoelectric materials through Zr doping

Ca3Co4−xZrxOy polycrystalline ceramics with small Zr substitution have been prepared through the classical solid-state method. X-ray diffraction data have shown that all samples are composed only of Ca3Co4O9 and Ca3Co2O6 phases. Moreover, by increasing Zr substitution up to 0.07, Ca3Co2O6 phase cont...

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Detalles Bibliográficos
Autores: Madre, M. A., Rasekh, Sh., Torres, M. A., Diez, J. C., Sotelo, Andres
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/181108
Acceso en línea:http://hdl.handle.net/10261/181108
Access Level:acceso abierto
Palabra clave:Ceramics
Doping
Electric properties
Microstructure
Power factor
Descripción
Sumario:Ca3Co4−xZrxOy polycrystalline ceramics with small Zr substitution have been prepared through the classical solid-state method. X-ray diffraction data have shown that all samples are composed only of Ca3Co4O9 and Ca3Co2O6 phases. Moreover, by increasing Zr substitution up to 0.07, Ca3Co2O6 phase content is decreased. Density measurements have revealed that all samples are very similar, with values around 74% of the theoretical density. Electrical resistivity is decreased in Zr-doped samples, with respect to the pure samples, while Seebeck coefficient is unchanged. Both factors lead to power factor values around 0.33 mW K−2 m−1 at 800°C in 0.07 Zr-doped samples, which are about 65% higher than those obtained for the undoped samples.