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 performed of the doping dependence of the chemical potential mu in (Bi, Pb)(2)Sr2Ca2Cu3O10+delta. The doping is varied by changing the oxygen content of the sample. The measured shift of the chemical potential is compared with present models for the doping behavior of mu in high-T-c materials. Our results show best agreement with the model in which the chemical potential is assumed to shift upon doping the parent insulating material.