  Irrespective of the class they belong to, all the hole doped high-Tc cuprate
superconductors show an anti-correlation between the superconducting transition
temperature and the characteristic pseudogap energy in the underdoped region.
The doping dependent pseudogap in the quasiparticle spectral density is
believed to remove low-energy electronic states and thereby reduce the
superconducting condensate. Impurities within the CuO2 plane, on the other
hand, break Cooper pairs in the unitarity limit and diminish superfluid
density. Both pseudogap in pure cuprates and impurity scattering in disordered
cuprates reduces Tc very effectively. In this study we have compared and
contrasted the mechanisms of Tc degradation due to pseudogap and impurity
scattering in hole doped cuprates. We have suggested a framework where both
these factors can be treated on somewhat equal footing. Beside impurity and
pseudogap dependent superconducting transition temperature, the proposed
scenario has been employed to investigate the disorder and hole content
dependent isotope exponent in high-Tc cuprates in this work.
