Thermoelectric power of samarium substituted Y1−xSmxBa2Cu3O7−δ superconducting pellets

The temperature dependence of the electrical resistivity and thermoelectric power of samarium substituted Y1−xSmxBa2Cu3O7−δ samples with x = 0, 0.2 and 0.4 is reported between TC0 and 300 K. With the increase of samarium content in YBCO, the magnitudes of both the electrical resistivity and the thermoelectric power decrease. However, the general features of the temperature variation of both ρ and S remain similar to that typically reported for ceramic oxide superconductors. Thermoelectric power of all the samples was found to be positive and it increases almost linearly with the decrease of temperature up to ∼120 K, before falling to zero at TC0. The measured data have been analysed and discussed on the basis of a “three-state model”. Our analysis shows an excellent agreement between the measured electrical resistivity and thermoelectric power data and those calculated using the above three-state model.