Insights into the Structural, Microstructural and Thermoelectric Properties of Ce/Cr co-doped CaMnO3 manganites

Korkmaz, L. ; Özçelik, C. ; Gürsul, M. ; Torres, M. A. (Universidad de Zaragoza) ; Madre, M. A. (Universidad de Zaragoza) ; Sotelo, A. (Universidad de Zaragoza) ; Özçelik, B.

Resumen: This study investigates the structural, microstructural, and thermoelectric properties of Cr-substituted Ca0.99Ce0.01Mn1-xCrxO3 materials synthesized via solid-state reaction method. X-ray diffraction (XRD) analysis confirms the single-phase orthorhombic structure (Pnma space group) for all compositions, with successful incorporation of Cr into the crystal structure. A slight decrease in lattice parameters is observed, attributed to the smaller ionic radius of Cr3+ compared to Mn3+. Field Emission scanning electron microscope (FESEM) reveals that Cr doping inhibits grain growth and induces crack formation, which significantly impacts electrical resistivity. The charge transport mechanism is well-described by Mott’s adiabatic small polaron model, with activation energy increasing with Cr doping. The Seebeck coefficient remains negative across all temperatures, indicating n-type conduction, and the highest power factor (∼0.35 mW/K2m) is achieved for the 0.03Cr-doped sample at 800 °C. These results highlight the potential of Cr-doped CaMnO3 as a cost-effective and scalable thermoelectric material, with performance comparable to that reported using more complex synthesis methods.

Idioma: Inglés

DOI: 10.1007/s10854-025-15116-z

Año: 2025

Publicado en: Journal of Materials Science: Materials in Electronics 36, 16 (2025), 1004 [12 pp.]
ISSN: 0957-4522

Financiación: info:eu-repo/grantAgreement/ES/DGA/T54-23R

Tipo y forma: Article (Published version)

Área (Departamento): Área Expresión Gráfica en Ing. (Dpto. Ingeniería Diseño Fabri.)
Área (Departamento): Área Cienc.Mater. Ingen.Metal. (Dpto. Ciencia Tecnol.Mater.Fl.)