Drastic modification of low temperature thermoelectric properties of Na-doped Bi2Sr2Co2Oy ceramics prepared via laser floating zone technique

Çetin, G. ; Özçelik, B. ; Gürsul, M. ; Madre, M.A. (Universidad de Zaragoza) ; Sotelo, A. (Universidad de Zaragoza) ; Adachi, S. ; Takano, Y.

Resumen: In this study, Bi2Sr2-xNaxCo2Oy (x = 0.0, 0.05, 0.075, 0.10, and 0.15) ceramic powders have been fabricated via the classical ceramic route, followed by a texturing process through the laser floating zone technique. XRD patterns show the thermoelectric phase as the major one. In addition, Na-substitution reduces the amount of secondary phases, when compared to the pure sample. SEM observations point out that grain orientation is significantly improved when Na-content is increased. Na-substitution reduces electrical resistivity from 35 (in pure samples) to 19.6 mO cm (in Na = 0.05 ones) at around room temperature, while Seebeck coefficient is, approximately, twice measured in Na-free. On the other hand, thermal conductivity is slightly lower in undoped samples (0.83 W/K m), when compared to the Na-substituted ones (1.10–1.40 W/K m) at room temperature, due to their lower electrical conductivity. Finally, ZT values are higher when the Na-content is increased, reaching 0.022 at around 400 K.

Idioma: Inglés

DOI: 10.1007/s10854-020-04119-7

Año: 2020

Publicado en: Journal of Materials Science: Materials in Electronics 31, 18 (2020), 15558-15564
ISSN: 0957-4522

Factor impacto JCR: 2.478 (2020)

Categ. JCR: ENGINEERING, ELECTRICAL & ELECTRONIC rank: 138 / 273 = 0.505 (2020) - Q3 - T2
Categ. JCR: PHYSICS, CONDENSED MATTER rank: 38 / 69 = 0.551 (2020) - Q3 - T2
Categ. JCR: PHYSICS, APPLIED rank: 83 / 160 = 0.519 (2020) - Q3 - T2
Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 215 / 333 = 0.646 (2020) - Q3 - T2

Factor impacto SCIMAGO: 0.488 - Atomic and Molecular Physics, and Optics (Q2) - Bioengineering (Q2) - Biomaterials (Q2) - Condensed Matter Physics (Q2) - Biophysics (Q2) - Electrical and Electronic Engineering (Q2) - Electronic, Optical and Magnetic Materials (Q2) - Biomedical Engineering (Q2)

Financiación: info:eu-repo/grantAgreement/ES/DGA-FEDER/T54-17R
Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/MAT2017-82183-C3-1-R

Tipo y forma: Article (PostPrint)

Área (Departamento): Área Cienc.Mater. Ingen.Metal. (Dpto. Ciencia Tecnol.Mater.Fl.)