The interplay of superconductivity and localization in Nd{2-x}Ce{x}CuO{4+\delta} single crystal films

TL;DR

This study investigates how nonstoichiometric disorder affects the electrical resistivity and superconducting transition in Nd{2-x}Ce{x}CuO{4+\delta} films, revealing a transition from metallic to insulating behavior due to disorder.

Contribution

It demonstrates the disorder-induced transition from superconducting to insulating states in Nd{2-x}Ce{x}CuO{4+\delta} films, highlighting the role of Anderson localization in this process.

Findings

Resistivity increases with disorder, reducing mean free path.

Superconducting transition temperature decreases and broadens with disorder.

Transition from homogeneous metallic to inhomogeneous insulating state observed.

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+\delta} single crystal films (x=0.15 and 0.18). It is shown that with increasing of $\delta$ 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+\delta} system to inhomogeneous dielectric one is described as Anderson-type disorder-induced transition in a two-dimensional electron system.