For the air-annealed samples of Bi2212 phase, hole concentration, p scales
very well with v, and the p-v line passes through the origin of the coordin
ates. Pb substitution drastically changed the shape of p-v line. In the ran
ge of 0.05 less than or equal tov less than or equal to0.125, p was fixed a
t 0.125. From these results, it is concluded that Pb controls the number of
holes in the CuO2 plane.