Unravelling the Effects of Calcium Substitution in BaGd2CoO5 Haldane Gap 1D Material and Its Thermoelectric Performance
| Autor: | Wenjie Xie, Duncan P. Fagg, Narendar Nasani, Gabriel Constantinescu, Shahed Rasekh, Anke Weidenkaff, Andrei V. Kovalevsky, D. Pukazhselvan |
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| Přispěvatelé: | Publica |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
cobalt compounds chemistry.chemical_element hole mobility thermal transport properties Calcium thermoelectric performance thermoelectricity thermoelectric application dimensionless figure of merit gadolinium compound Thermal conductivity bismuth compounds Seebeck coefficient Thermoelectric effect IV-VI semiconductor Figure of merit thermal conductivity Physical and Theoretical Chemistry Thermoelectrics calcium calcium compounds electrical conductivity Condensed matter physics Substitution (logic) low thermal conductivity Thermoelectric materials Surfaces Coatings and Films Electronic Optical and Magnetic Materials General Energy electrical performance chemistry Haldane gap thermo-electric materials barium compounds carrier concentration hall mobility |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | Ecobenign and high-temperature-stable oxides are considered a promising alternative to traditional Bi2Te3-, Bi2Se3-, and PbTe-based thermoelectric materials. The quest for high-performing thermoelectric oxides is still open and, among other challenges, includes the screening of various materials systems for potentially promising electrical and thermal transport properties. In this work, a new family of acceptor-substituted Haldane gap 1D BaGd2CoO5 dense ceramic materials was characterized in this respect. The substitution of this material with calcium results in a general improvement of the electrical performance, contributed by an interplay between the charge carrier concentration and their mobility. Nevertheless, a relatively low electrical conductivity was measured, reaching ∼5 S/cm at 1175 K, resulting in a maximum power factor of ∼25 mW/(K × m2) at 1173 K for BaGd1.80Ca0.20CoO5. On the other hand, the unique anisotropic 1D structure of the prepared materials promotes efficient phonon scattering, leading to low thermal conductivities, rarely observed in oxide electroceramics. While the BaGd2-xCaxCoO5 materials show attractive Seebeck coefficient values in the range 210-440 mV/K, the resulting dimensionless figure of merit is still relatively low, reaching ∼0.02 at 1173 K. The substituted BaGd2-xCaxCoO5 ceramics show comparable thermoelectric performance in both inert and air atmospheres. These features highlight the potential relevance of this structure type for thermoelectric applications, with future emphasis placed on methods to improve conductivity. |
| Databáze: | OpenAIRE |
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