The effect of inhomogeneous phase on the critical temperature of smart meta-superconductor MgB2

TL;DR

This study investigates how inhomogeneous phases in a smart meta-superconductor structure influence the critical temperature of MgB2, revealing that doping and electric fields can modulate T_C in specific ways.

Contribution

It introduces a novel smart meta-superconductor structure with inhomogeneous phases and explores their effects on T_C, including electric field influences, which is a new approach in superconductor research.

Findings

Doping with Y2O3:Eu3+ nanosheets increases T_off C by 1.2 K.

Electric current slightly raises T_on C in doped samples.

Inhomogeneous phases affect T_off C differently under electric fields.

Abstract

The critical temperature (TC) of MgB2, one of the key factors limiting its application, is highly desired to be improved. On the basis of the meta-material structure, we prepared a smart meta-superconductor structure consisting of MgB2 micro-particles and inhomogeneous phases by an ex situ process. The effect of inhomogeneous phase on the TC of smart meta-superconductor MgB2 was investigated. Results showed that the onset temperature (Ton C) of doping samples was lower than those of pure MgB2. However, the offset temperature (Toff C) of the sample doped with Y2O3:Eu3+ nanosheets with a thickness of 2~3 nm which is much less than the coherence length of MgB2 is 1.2 K higher than that of pure MgB2. The effect of the applied electric field on the TC of sample was also studied. Results indicated that with the increase of current, Ton C is slightly increased in the samples doping with different inhomogeneous phases. When increasing current, the Toff C of the samples doped with nonluminous inhomogeneous phases was decreased. However, the Toff C of the luminescent inhomogeneous phase doping samples increased and then decreased as increasing current.