abstract
Ceramics with nominal BaFe(12)Ox composition were processed through laser floating zone technique from 25 to 200 mm/h growth rates. These processing conditions were found to promote microstructural differences between the outer and inner parts of the rods, being more pronounced at higher growth rates. Along with the higher microstructural inhomogeneity, the samples grown at 100 and 200 mm/h display reasonable n-type thermoelectric properties provided by BaFe18Ox phase formation. Their highest power factor measured at 800 degrees C is comparable to the best observed so far in oxide ceramic materials, with additional advantage of high abundance and low costs of Fe2O3, and BaCO3 precursors. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
keywords
MICROSTRUCTURE; PERFORMANCES; CERAMICS; CA
subject category
Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering
authors
Ferreira, NM; Costa, FM; Kovalevsky, AV; Madre, MA; Torres, MA; Diez, JC; Sotelo, A
our authors
Andrei Kavaleuski
Principal Researcher
Nuno Miguel Freitas Ferreira
Post-Doc Fellowshipacknowledgements
A Sotelo, M. A. Madre, J. C. Diez, and M. A. Tones acknowledge the Gobierno de Aragon (Grupos de Investigacion Consolidados 112 and T87), and the MINECO-FEDER (MAT2013-46505-C3-1-R) for funding. N.M. Ferreira, A.V. Kovalevsky and F.M. Costa acknowledge the i3N (UID/CTM/50025/2013) and CICECO-Aveiro Institute of Materials (UID/CTM/50011/2013), financed by FCT/MEC and FEDER under the FT2020 Partnership Agreement. The support from FCT (Portugal) grants SFRH/BPD/111460/2015 and IF/00302/2012, are also acknowledged.