DOPING DEPENDENCE OF THE CHEMICAL-POTENTIAL IN CUPRATE HIGH-T-C SUPERCONDUCTORS .2. (BI,PB)(2)SR2CA2CU2O10+DELTA

Using X-ray photoelectron spectroscopy, a systematic study is performe d of the doping dependence of the chemical potential mu in (Bi, Pb)(2) Sr2Ca2Cu3O10+delta. The doping is varied by changing the oxygen conten t of the sample. The measured shift of the chemical potential is compa red with present models for the doping behavior of mu in high-T-c mate rials. Our results show best agreement with the model in which the che mical potential is assumed to shift upon doping the parent insulating material.