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Title: Thermoelectric and magnetic properties of Ca{sub 3}Co{sub 4–x}Cu{sub x}O{sub 9+δ} with x = 0.00, 0.05, 0.07, 0.10 and 0.15

Graphical abstract: - Highlights: • Resistivity of all the samples exhibits nonmetallic to metallic behavior in the low temperature region. • Ca{sub 3}Co{sub 3.85}Cu{sub 0.15}O{sub 9+δ} shows the highest dimensionless figure of merit. • The observed effective magnetic moments decrease with increasing Cu content. - Abstract: Ca{sub 3}Co{sub 4–x}Cu{sub x}O{sub 9+δ} (x = 0.00, 0.05, 0.07, 0.10 and 0.15) samples were prepared by conventional solid-state synthesis and their thermoelectric properties were systematically investigated. The thermopower of all the samples was positive, indicating that the predominant carriers are holes over the entire temperature range. Ca{sub 3}Co{sub 3.85}Cu{sub 0.15}O{sub 9+δ} had the highest power factor of 2.17 μW cm{sup −1} K{sup −2} at 141 K, representing an improvement of about 64.4% compared to undoped Ca{sub 3}Co{sub 4}O{sub 9+δ}. Magnetization measurements indicated that all the samples exhibit a low-spin state of cobalt ions. The observed effective magnetic moments decreased with increasing copper content.
Authors:
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Publication Date:
OSTI Identifier:
22285220
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 48; Journal Issue: 11; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COBALT IONS; COPPER; MAGNETIC MOMENTS; MAGNETIC PROPERTIES; MAGNETIZATION; OXIDES; POWER FACTOR; TEMPERATURE RANGE 0065-0273 K; THERMAL CONDUCTIVITY; THERMOELECTRIC PROPERTIES; X-RAY DIFFRACTION