Normal state resistivity of YBa2Cu3O7-delta/PrB2 Cu2.8Ga0.2O7-delta c-axissuperlattices: Evidence for an underdoping effect of YBa2Cu3O7-delta

We measured the ab-plane resistivity of c-axis YBa2Cu3O7-delta /PrBa2Cu2.8G a0.2O7 superlattices grown by pulsed laser deposition, from Te to 325 K. Th e normal-state resistivity and the fluctuation regime above Te were studied for different thickness of YBa2Cu3O7-delta and PrBa2Cu2.8Ga0.2O7-delta in the superlattice period. As the concentration of PrBa2Cu2.8Ga0.2O7-delta is raised the T-C decreases and the resistivity increases. Evidence is given for an underdoping effect in the YBa2Cu3O7-delta layers and our measurement s are compared to similar measurements on oxygen-deficient YBa2Cu3O7-delta thin films, grown on the same equipment. They are also compared to measurem ents on YBa2Cu3-xCoxO7-delta single crystals made by other groups. We prese nt here the different measurements and investigate the mechanisms that coul d be held responsible for this depletion in charge carriers.