Tailoring Ca0.99Ce0.01MnO3 properties using Mo doping and its integration in a power generation thermoelectric module

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

Resumen: In the present study, we examined both the crystal structure and thermoelectric behavior of Ca0.99Ce0.01Mn1-xMoxO3 compositions, with Mo concentrations set at x = 0, 0.01, 0.03, 0.05, and 0.10. From XRD experiment, it is observed that most of the peaks can be indexed in a Pnma space group. Furthermore, Mo has effectively substituted Mn into the unit cell revealed by the shift of the diffraction peaks towards lower angles. SEM images showed a grain refinement with the increase in Mo doping, suggesting that it acts as grain growth inhibitor. Moreover, a decrease of porosity is observed when the amount of dopant is raised up to 0.05, increasing for higher Mo content. EDS analysis conducted on various regions of the samples shows that the grain compositions closely match the nominal values. Resistivity data show that the undoped sample exhibits both metallic-like and semiconducting-like behavior, whereas Mo doping induces metallic-like behavior throughout the entire temperature range. The lowest resistivity at 800 °C (∼ 6.5 mΩ cm) was recorded for the 0.10 Mo-substituted sample, which is comparable to the values found in the 0.03 and 0.05 Mo-doped samples, and significantly lower than that of the undoped sample. The evolution of the Seebeck coefficient as a function of composition and temperature demonstrated that all samples exhibit negative S values within the measured range of temperatures. The highest |S| values at 800 °C were measured in the Mo-free samples (213 μV/K), very close to that of the 0.01Mo-doped samples (207 μV/K). Highest PF measured at 800 °C were obtained in 0.01Mo-doped samples (∼ 0.36 mW/K2m), which are between 13 and 30 % higher than those obtained in 0.0, 0.03, and 0.05Mo-doped samples. Finally, a power generation thermoelectric module with 17 p-n pairs, and 50 × 50 mm2 surface, has been successfully prepared using 0.01Mo doped samples and Ca2.93Sr0.07Co4O9, which has produced 0.045 W maximum power at 900 °C hot-side temperature, under 358 °C internal ΔT. Taking into account the module surface (2500 mm2) and the maximum power generated (45 mW), a high power density of 18 W/m2 has been obtained.

Idioma: Inglés

DOI: 10.1016/j.mseb.2025.118861

Año: 2026

Publicado en: Materials Science and Engineering B: Solid-State Materials for Advanced Technology 323 (2026), 118861 [9 pp.]
ISSN: 0921-5107

Financiación: info:eu-repo/grantAgreement/ES/DGA/T54-23R
Financiación: info:eu-repo/grantAgreement/ES/MICIU/CEX2023-001286-S

Tipo y forma: Artículo (PostPrint)

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