Effect of grain size on electric resistivity and thermopower of (Ca2.6Bi0.4)Co4O9 thin films
2003; American Institute of Physics; Volume: 95; Issue: 2 Linguagem: Inglês
10.1063/1.1631732
ISSN1520-8850
AutoresYuqin Zhou, Ichiro Matsubara, Woosuck Shin, Noriya Izu, Norimitsu Murayama,
Tópico(s)Magnetic and transport properties of perovskites and related materials
Resumo( Ca 2.6 Bi 0.4 ) Co 4 O 9 thin films were deposited on MgO single crystal substrates by the spin coating method. Films with different grain sizes (50–500 nm) were obtained by preparing at different temperatures. Films were polycrystalline in nature and oriented preferentially in the (001) direction. Electrical resistivity and thermopower were measured to study the effect of the grain size on the thermoelectric properties. Hall carrier concentrations of the films are dependent on the grain size. The film with a smaller grain size has a lower carrier concentration, a larger resistivity, and a higher thermopower. The thermoelectric power factor is related to the grain size and shows a maximum for the film with grain size of about 100 nm.
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