CARRIER DOPING AND INTERLAYER COUPLING IN HTSC SINGLE-CRYSTALS

Experimental results of the effect of carrier doping on the irreversib ility lines in (La,Sr)(2)CuO4-delta and Bi2Sr2CaCu2O8+delta Single cry stals are summarized. As a function of Sr or oxygen contents, systemat ic and dramatic widening of the irreversible regions in the B - T phas e diagram was observed in both systems. The present study suggests the critical importance of carrier concentration which directly affects t he interlayer coupling strength and dimensionality of the flux line la ttice in all the layered HTSC compounds as a universal feature.