@article{34024,
  author = {Ramamoorthy Ramesh and M.S Hegde and C.C Chang and J.M Tarascon and S.M Green and H.L Luo},
  title = {Doping mechanism in Bi(Pb)-Sr-Ca-Cu-O superconductors},
  abstract = {A model that explains the doping mechanism in Bi(Pb)-Sr-Ca-Cu-O superconductor is presented. X-ray microanalysis reveals that the excess oxygen can be accounted for by the exact stoichiometry of the n=2 and 3 phases. We show that the presence of excess oxygen associated with the structural modulation in the compound is not sufficient to explain the hole concentration required by the transition temperature observed. Using a bond valence argument, we show that the effective valence of the Bi ion in the BiO bilayers is smaller than the expected value of +3, due to the incomplete oxygen coordination around the Bi ion. The model qualitatively explains the observations of lowering of T c with Er (or Tm) doping or oxygen annealing. The role of Pb addition is suggested to be one of altering the thermodynamics and kinetics of formation of the n=3 phase.},
  year = {1989},
  journal = {Journal of Applied Physics},
  volume = {66},
  number = {10},
  pages = {4878-4885},
  issn = {00218979},
  doi = {10.1063/1.343806},
  note = {cited By 36},
  language = {eng},
}