Hole distribution and T-c suppression in Y1-xPrxBa2Cu3O7

A model Hamiltonian, which includes the components of the CuO2 planes, CuO3 chains, and the Pr-O hybridization, is considered to describe the electron ic structure of Y1-xPrxBa2Cu3O7. We make the coherent-potential approximati on calculation for the Hamiltonian to present the variation of the distribu tion of the holes against the Pr concentration. The results show that the h ole transfer is mainly from the pd sigma band to the p-f hybridization band , and a small reduction of the holes residing on the CuO3 chains is caused by the Pr doping. A metal-nonmetal transition around x = 0.5 can be obtaine d according to our calculation, We present a quantitative interpretation fo r the T-c suppression in terms of the combination of hole-transfer and magn etic scattering effects. Moreover, the enhancement of the magnetic pair bre aking due to the presence of a normal-state pseudogap is also considered. C onsequently, we give a satisfactory explanation of T-c suppression for the whole Pr-doping region. [S0163-1829(99)13701-9].