  A comparative study has been made of iodine-intercalated
Bi$_{2}$Sr$_{2}$Ca$_{1}$Cu$_{2}$O$_{x}$ single crystal and 1 atm O$_{2}$
annealed Bi$_{2}$Sr$_{2}$Ca$_{1}$Cu$_{1}$O$_{x}$ single crystal using AC
susceptibility measurement, X-ray photoemission (XPS) and angle-resolved
ultraviolet photoemission spectroscopy (ARUPS). AC susceptibility measurement
indicates that O$_{2}$-doped samples studied have T$_{c}$ of 84 $^{o}$K,
whereas T$_{c}$ of Iodine-doped samples studied are 80 $^{o}$K. XPS Cu 2p core
level data establish that the hole concentration in the CuO$_{2}$ planes are
essentially the same for these two kinds of samples. ARUPS measurements show
that electronic structure of the normal states near the Fermi level has been
strongly affected by iodine intercalation. We conclude that the dominant effect
of iodine doping is to alter the interlayer coupling.
