KIirat, G.Aksan, M. A.Rasekh, Sh.Madre, M. A.Diez, J. C.Sotelo, A.2024-08-042024-08-0420150272-88421873-3956https://doi.org/10.1016/j.ceramint.2015.04.156https://hdl.handle.net/11616/97133In this study, the effect of Yb-substitution on the structural, electrical and thermal transport properties of the Ca3Co4O9+delta system has been investigated in the low temperature region (between 10 and 300 K). The resistivity of samples increases with raising the Yb-concentration in the system. All the samples show a metal-semiconductor transition below 85 K. In the analysis based on Strongly Correlated Fermi Liquid Model, an increased bandwidth and a reduced electronic correlation are found. It has also been found that the energy gap, E-0, value also decreases with Yb-substitution. The samples show positive thermoelectric power, indicating that dominant charge carriers are holes in all the samples. The thermoelectric power value decreases with Yb-substitution. From Mott equation, it is determined that the Fermi energy and hole concentration decrease in the Yb-susbtituted samples, compared to the undoped ones. Thermal conductivity, kappa, is decreased in about 50% of the measured in undoped samples for the 0.01 and 0.03 Yb-doped samples at 300 K. Highest figure of merit, ZT, value is found to be 5.4 10(-3) at 300 K for the unsubstituted sample and the ZT value decreases by the substitution. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.eninfo:eu-repo/semantics/closedAccessThermal conductivityCeramicsDopingElectrical transportArticle4110125291253410.1016/j.ceramint.2015.04.1562-s2.0-84955199280Q1WOS:000362860900002Q1