resumo
This work assesses the feasibility of processing CuFe1-xNixO2 (x = 0, 0.02) using the Laser Floating Zone (LFZ) technique to grow fibres with different pulling rates, to tune their thermoelectric performance. Structural analysis showed CuFeO2 as the major phase. Formation of secondary phases is promoted by Ni addition, diminishing with decreasing pulling rate. Grain alignment and crystallite size of the fibres increase with the puling rate and doping. Electrical conductivity is enhanced by decreasing the pulling rate, while Ni-doping decreases the conductivity, and Seebeck coefficient demonstrates quite complex behaviour. Thermal conductivity decreases with temperature and with the pulling rate and Ni-doping. A maximum ZT value of 0.17 was achieved for 10 mm h(-1) sample at 1000 K for pure, and 700 K for Ni-doped samples. These ZT values are higher than found in the literature, demonstrating the feasibility of the LFZ method for processing thermoelectric delafossites, indicating a proper optimisation process.(c) 2022 Elsevier B.V. All rights reserved.
palavras-chave
THIN-FILMS; PERFORMANCE; GROWTH
categoria
Chemistry; Materials Science; Metallurgy & Metallurgical Engineering
autores
Ferreira, NM; Grillo, JG; Ferro, MC; Dura, OJ; Madre, MA; Kovalevsky, AV; Costa, FM; Sotelo, A
nossos autores
Andrei Kavaleuski
Investigador principal
Marta Ascenção Carmona Ferro
Técnico de Laboratório
Nuno Miguel Freitas Ferreira
Bolseiro de pós-DoutoramentoProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
agradecimentos
This work was developed within the scope of the project i3N (LA/P/0037/2020 & UIDB/50025/2020 & UIDP/50025/2020) and CICECO-Aveiro Institute of Materials (UIDB/50011/2020 & UIDP/50011/2020), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. This work was funded by national funds (OE), through FCT - Fundacao para a Ciencia Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. M. A. Madre and A. Sotelo acknowledge the Spanish MINECO-FEDER (Project MAT2017-82183-C3-1-R) and Gobierno de Aragon-FEDER (Research Group T 54-20R) for funding. The support of the project POCI-01-0145-FEDER-031875, financed by COMPETE 2020 Program and National Funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement, is greatly acknowledged.