Long-term high-temperature stability of directionally grown [Bi2Ba2O4]p[CoO2] rods

[Bi2Ba2O4]p[CoO2] thermoelectric ceramics have been successfully grown from the melt using the laser floating zone method, followed by a thermal treatment at 700°C under air between 0 and 1532 h. The microstructural, thermoelectric, and mechanical properties were evaluated as a function of the therm...

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Detalles Bibliográficos
Autores: Diez, J. C., Madre, M. A., Torres, M. A., Rasekh, Sh., Sotelo, Andres
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/148749
Acceso en línea:http://hdl.handle.net/10261/148749
Access Level:acceso abierto
Palabra clave:Power factor
Flexural strength
Aging
Cobalt oxides
Thermoelectricity
Descripción
Sumario:[Bi2Ba2O4]p[CoO2] thermoelectric ceramics have been successfully grown from the melt using the laser floating zone method, followed by a thermal treatment at 700°C under air between 0 and 1532 h. The microstructural, thermoelectric, and mechanical properties were evaluated as a function of the thermal treatment length. Microstructure has shown that as-grown samples are composed of thermoelectric grains, together with a relatively high amount of secondary phases. Thermal treatment decreased the number and amount of secondary phases, producing nearly single-phase samples after 384 h. Consequently, the thermoelectric properties evaluated through the power factor showed a slight increase with the thermal treatment length, mainly due to the decrease of electrical resistivity, while the Seebeck coefficient was nearly unchanged. On the other hand, flexural strength was practically constant after 24 h thermal treatment.