Thermoelectric power and thermal conductivity study of the Y3Ba5Cu8Ox system

In the present study, the effect of heat treatment conditions on the structural/microstructural, electrical and transport properties, such as thermoelectric power and thermal conductivity, of the Y-358 system was investigated. The Y-123 phase instead of Y-358 were obtained with heat treatments. XRD and SEM analyses showed that the best structural formation was obtained for the sample prepared at 900 °C for 24 h. All the samples exhibited the Tc value around 91 K. Positive S(T) value was obtained in all the samples. S(T) data was analyzed by “Two band model with linear T-term”. In thermal conductivity of the samples, small peak with broad maximum was found just below Tc, unlike that of the HTc cuprates.