Inhomogeneous Phase Effect of Smart Meta-Superconducting $\hbox {MgB}_{2}$

Abstract

The inhomogeneous phase of a smart meta-superconductor has a great effect on its superconductivity. In this paper, the effect of concentration, dimensions, electroluminescence (EL) intensity, and distribution of the inhomogeneous phase on the superconducting critical temperature $(T_{C})$ has been systematically investigated. An ex situ solid sintering was utilized to prepare smart meta-superconducting $\hbox {MgB}_{2}$ doped with six kinds of electroluminescent materials, such as $\hbox {YVO}_{4}{:}\hbox {Eu}^{3+}$ and $\hbox {Y}_{2}\hbox {O}_{3}{:}\hbox {Eu}^{3+}$ flakes. Elemental mappings through energy dispersive spectroscopy (EDS) show that the inhomogeneous phase is comparatively uniformly dispersed around the $\hbox {MgB}_{2}$ particles; thus V, Y, and Eu were accumulated at a small area. The measurement results show that the optimum doping concentration of the meta-superconducting $\hbox {MgB}_{2}$ is 2.0 wt%. The offset temperature ($T_{C}^{{ off}}$) of the sample doped with 2.0 wt% dopant A is 1.6 K higher than that of pure $\hbox {MgB}_{2}$. The improvement in $T_{C}^{{ off}}$ is likely related to the sizes, thickness, and EL intensity of the inhomogeneous phase of $\hbox {MgB}_{2}$ smart meta-superconductor. This experiment provides a novel approach to enhance $T_{C}$.