Superconducting Properties and Phase Diagram of Indirectly Electron-Doped (Sr1-xLax)Fe2As2 Epitaxial Films Grown by Pulsed Laser Deposition

TL;DR

This study investigates the superconducting properties and phase diagram of indirectly electron-doped Sr1-xLaxFe2As2 epitaxial films, revealing similar behavior to directly doped counterparts and establishing the robustness of superconductivity against doping site variations.

Contribution

It demonstrates that indirect electron doping via La substitution produces superconducting SrFe2As2 films with properties comparable to direct doping, expanding understanding of doping effects in 122-type iron pnictides.

Findings

Maximum Tc of 20.8 K achieved.

Superconductivity suppressed resistivity anomaly.

Electronic phase diagram similar to direct doping case.

Abstract

A non-equilibrium phase (Sr1-xLax)Fe2As2 was formed by epitaxial film-growth. The resulting films emerged superconductivity along with suppression of the resistivity anomaly that is associated with magnetic and structural phase transitions. The maximum critical temperature was 20.8 K, which is almost the same as that of directly electron-doped Sr(Fe1-xCox)2As2. Its electronic phase diagram is much similar to that of Sr(Fe1-xCox)2As2, indicating that the difference in the electron doping sites does not influence the superconducting properties of 122-type SrFe2As2.