THERMOELECTRIC-POWER AND SUPERCONDUCTING TRANSITION IN HIGH-TEMPERATURE SUPERCONDUCTORS DY1-XPRXBA2CU3O7

The thermoelectric power (S) and superconducting transition temperatur e (T-c) have been systematically measured for a series of Dy1-xPrxBa2C u3O7-d with x from 0 to 0.6. Our results show that S increases progres sively with increasing x while T, decreases. Based on the empirical re lation between S and the carrier concentration (n), n has been extract ed. The result shows a clear reduction of n with increasing x, with a linear relation for x > 0.15, This hole reduction is consistent with t he hole-depletion model proposed by Liechtenstein and Mazin. Our T-c-n data are in a remarkable agreement with the universal parabolic T-c-n relation, demonstrating that the T-c suppression with Pr doping comes mainly from the hole-depletion effect.