Publication Date:
2013-05-26
Description:
Highly c-axis-oriented Ca 3 Co 4− x Cu x O 9+δ ( x = 0, 0.1, 0.2, and 0.3) thin films were prepared by chemical solution deposition on LaAlO 3 (001) single-crystal substrates. X-ray diffraction, field-emission scanning electronic microscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible absorption spectrums were used to characterize the derived thin films. The solubility limit of Cu was found to be less than 0.2, above which [ Ca 2 ( Co 0.65 Cu 0.35 ) 2 O 4 ] 0.624 CoO 2 with quadruplicated rock-salt layers was observed. The electrical resistivity decreased monotonously with increasing Cu -doping content when x ≤ 0.2, and then slightly increased with further Cu doping. The Seebeck coefficient was enhanced from ~100 μV/K for the undoped thin film to ~120 μV/K for the Cu -doped thin films. The power factor was enhanced for about two times at room temperature by Cu doping, suggesting that Cu -doped Ca 3 Co 4 O 9+δ thin films could be a promising candidate for thermoelectric applications.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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