Influence of oxygen deficiency on the thermoelectric power of Y1Ba2Cu3O7-x

In this paper we report measurements of the thermoelectric power on a series of Y1Ba2Cu3O7-x specimens with varying amounts of oxygen deficiency obtained by changing the cooling rate of the sintered specimens. The specimens have been characterized by X-ray diffraction measurements, electric resistivity and oxygen contents. The temperature variation of the thermopower reveals a peak just before the onset of superconducting transition. We examine possible theoretical explanations of this anomaly. In particular we argue that this anomaly is associated with the pairing fluctuations in the normal state close toT c . We present some theoretical results in support of this conclusion.