Pr-induced superconductivity suppression in YxPr1−xBa2Cu4O8 probed by soft-X-ray absorption spectroscopy: a comparative studies of YxPr1−xBa2Cu4O8 and YxPr1−xBa2Cu3O7

The variation of hole states with Pr doping for YxPr1−xBa2Cu3O7 and YxPr1−xBa2Cu4O8 has been investigated by O K-edge X-ray absorption spectroscopy. Upon Pr substitution, Tc suppression rate in YxPr1−xBa2Cu4O8 is slower than that in YxPr1−xBa2Cu3O7. For both systems, hole carriers in the CuO2 planes and CuO chains decrease monotonically with increasing Pr doping level. The depletion rate of hole carriers in the CuO2 planes with Pr doping in YxPr1−xBa2Cu4O8 is considerably slower than that in YxPr1−xBa2Cu3O7. The oxygen content affects the depletion rate of hole carriers in cuprates with Pr doping.