NONHOMOGENEOUS CHARGE-DISTRIBUTION IN DOPED LAYERED SUPERCONDUCTING COMPOUNDS

The effect of doping on the charge distribution inside layered superconducting compounds is considered. The model proposed by Di Stasio et al. [1] (Phys. Rev. Lett. 64 (1990) 2827) for undoped materials is extended to include the modifications induced by doping. The extra charge added by doping is distributed in a nonhomogeneous way between the different layers. The charge depletion in the central layers, reported for the undoped material, can be enhanced or reduced by a suitable dopant. The implications for the density of states and critical temperature are discussed.