The interplay of superconductivity and localization in Nd 2− xCe xCuO 4+ δ single crystal films

Abstract

The influence of nonstoichiometric disorder on the in-plane resistivity and SC-transition has been investigated for Nd 2− x Ce x CuO 4+ δ single crystal films ( x=0.15 and 0.18). It is shown that with increasing of δ the in-plane normal state resistivity increases (the mean free path diminishes) and SC-transition temperature decreases with essential broadening of the transition region. The observed evolution from homogeneous metallic (and superconducting) Nd 2− x Ce x CuO 4+ δ system to inhomogeneous dielectric one is described as Anderson-type disorder-induced transition in a two-dimensional electron system.