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Communication Dans Un Congrès Année : 2017

Oxide Thermoelectrics Nanostructured by Spinodal Decomposition

A. Verchere
  • Fonction : Orateur
  • PersonId : 1032804
S. Mishra
S. Le Floch
Gilbert Fantozzi
  • Fonction : Auteur
  • PersonId : 883180
S. Daniele
S. Pailhès

Résumé

High-efficiency thermoelectric (TE) materials are important for power-generation devices that are designed to convert waste heat into electrical energy or to use in solid-state refrigeration. These applications require innovative materials which not only possess high conversion efficiency (related to high dimensionless number called figure of merit, "ZT" which is a combination of three material properties: Seebeck coefficient, electrical conductivity and thermal conductivity , but should also be no toxic and have high chemical stability in air, over a wide temperature range such as oxide materials. From last decade, a major breakthrough in the field of TE came by designing nanostructures that scatter phonons more effectively than electrons, so that the thermal conductivity is reduced more than the electrical conductivity. Herein we present a cheap and thermodynamically driven process to produce intra-granular nanostructures in bulk materials: the spinodal decomposition in the Nb5+-doped SnO2-TiO2 system via an innovative molecular approach. Such in-situ partitioning takes advantage to produce nanostructuration with coherent interfaces. While classical approach based on SnO2 (nano)powders mixing faces trouble to sinter dense ceramics, our bottom-up approach, trough synthesis of mixed TixSn1-xO2 (x = 0.25; 0.5; 0.75) rutile nanoparticles, suppress pure SnO2 grains and allow full densification at low temperature by SPS process. Impact of the pressure, heating rate and soaking time of SPS process onto the densification, the nano-structuration and the dopant distribution will be addressed towards the thermoelectric properties.
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Dates et versions

hal-01808470 , version 1 (05-06-2018)

Identifiants

  • HAL Id : hal-01808470 , version 1

Citer

A. Verchere, S. Mishra, S. Le Floch, Gilbert Fantozzi, S. Daniele, et al.. Oxide Thermoelectrics Nanostructured by Spinodal Decomposition. EMRS 2017 Spring meeting, May 2017, Strasbourg France. ⟨hal-01808470⟩
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