Effect of oxygen incorporation on normal and superconducting properties of MgB2 films

TL;DR

This study investigates how oxygen incorporation affects the superconducting and normal properties of MgB2 films, revealing that oxygen doping enhances critical current densities and upper critical fields, making the material more suitable for high-field applications.

Contribution

It demonstrates that oxygen doping during MgB2 film growth improves high-field superconducting properties, a novel approach for enhancing superconductor performance.

Findings

Oxygen is distributed within and between MgB2 grains.

High critical current densities (~4x10^5 A/cm^2 at 8 T) are achieved.

Oxygen doping increases the upper critical field (>45 T).

Abstract

Oxygen was systematically incorporated in MBE grown MgB2 films using in-situ post-growth anneals in an oxygen environment. Connectivity analysis in combination with measurements of the critical temperature and resistivity indicate that oxygen is distributed both within and between the grains. High values of critical current densities in field (~4x10^5 A/cm^2 at 8 T and 4.2 K), extrabolated critical fields (>45 T) and slopes of critical field versus temperature (1.4 T/K) are observed. Our results suggest that low growth temperatures (300oC) and oxygen doping (>0.65%) can produce MgB2 with high Jc values in field and Hc2 for high-field magnet applications.