Enhancing electrical properties in CaMnO 3 ‐based ceramics: The impact of single doping with different elements
Year: 2025
Type: article
Abstract: This study explores the effect of single doping with different rare earth elements (Y, La, and Yb) on the structural, morphological and electrical properties of CaMnO 3 bulk ceramics, aiming to improve their thermoelectric performance. Ca (1‐ x ) R x MnO 3 (R = Y, La, Yb; x = 0, 0.05, 0.10) samples were synthesized via a solid‐state reaction. XRD analysis confirmed the thermoelectric CaMnO 3 phase as the major one, with orthorhombic perovskite structure. Small amounts of secondary phases (CaMn 2 O 4 and Mn 2 O 3 ) were also detected in some doped samples. The addition of dopants influenced the unit cell parameters, producing a shift to lower 2 θ angles, confirming their incorporation into the ceramic structure. SEM micrographs revealed a significant reduction in grain size upon doping. Electrical resistivity measurements showed a metallic behavior for all doped samples. The Y‐doped samples exhibited the highest resistivity values while the Yb‐doped samples showed the lowest values (6.8 mΩ cm for the 0.10 doped one), which are among the lowest found in literature for this compound. The Seebeck coefficient values show minor changes for 0.05 doped samples when they decreased with increasing concentration of dopant. Consequently, the highest values were observed for 0.05‐doped sample (−215 µV/K), independently of the dopant. This value is much higher than the ones typically reported in the literature. The highest value of the power factor was calculated for the 0.05 Yb doped sample, reaching approximately 0.56 mW/K 2 ·m at 800°C. This value is higher than the best presented in the literature for this compound, to the best of our knowledge, and suggests that Yb 3+ doping greatly enhances the high‐temperature thermoelectric performance of bulk CaMnO 3 ceramics, making it a promising dopant for high‐efficiency thermoelectric materials.
DOI: 10.1111/jace.20372
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funders: Ministerio de Ciencia, Innovación y Universidades, Ministério da Ciência, Tecnologia e Ensino Superior, Universidad de Zaragoza, Gobierno de Aragón, Centro de Investigação em Materiais Cerâmicos e Compósitos, Horizon 2020 Framework Programme, Fundação para a Ciência e a Tecnologia, Agencia Estatal de Investigación, H2020 Marie Skłodowska-Curie Actions
Awards: CICECO-Instituto de Materiais de Aveiro, G1164167701, G1792064735, G1857155500, G1918496035, G2157332709, G2262748287, G243576772, G2655056113, G2777725491, G3010950644, G3020948319, G3082032993, A Quest for High Performance Ceramic Thermoelectric Modules, G3211096322, G3283876815, G337186154, G3444219832, G3480869486, G3557867621, G3592153812, G3615221479, G3783317134, G3845300180, G3945525359, G4046065984, G404710190, G425668148, G4293424916, G4782308234, G4906489308, Centro de Tecnologia Mecânica e Automação, G4940801717, G507957923, G5218434153, CICECO – Instituto de Materiais de Aveiro, G5402099700, G5454278309, G5541790479, G5808125593, G5820046185, Centro de Tecnologia Mecânica e Automação, G6193069014, CICECO-Instituto de Materiais de Aveiro, G6410266313, Láser para Energía y Materiales Avanzados (LEMA), G683931746, G6928308163, G6997658380, G7169023097, G7403097962, G7673090174, G7867053572, G7953547385, G841320811, G8930230220, G983705713
OpenAlex ID: W4406146531