Low temperature electrical and thermal transport properties of the Ca3-xSbxCo4O9 system
Küçük Resim Yok
Tarih
2012
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, the Ca3-xSbxCo4O9 (x = 0.0, 0.5, 0.75 and 1.0) system was fabricated using solid-state reaction technique. From the XRD analysis, it was found that increase of the Sb concentration in the system caused formation of impurity phases and therefore a distortion in the main lattice. The SEM-EDX results showed that the grain size reduced with increasing Sb in the Ca3Co4O9 system. The resistivity, rho, value increased with increasing the Sb-content and insulating behavior was obtained as the temperature was decreased. The samples fabricated have positive thermoelectric power, S, value, suggesting that holes are dominant charge carriers in the samples. S value decreased with decreasing the temperature. The Fermi energy, E-F , and the carrier concentration, n, decreased by the Sb-substitution. The Sb-substitution caused a decrease of thermal conductivity, kappa which is due to reduction of the phonon thermal conductivity, kappa(ph,) in the system. Figure of merit, ZT, value decreased significantly due to strongly increase in rho. The impurities, defects and distortion with substitution of Sb are responsible for large variation on electrical and thermal transport properties.
Açıklama
Anahtar Kelimeler
Thermoelectric Properties, Performance
Kaynak
Journal of Materials Science-Materials in Electronics
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
23
Sayı
12