Inhomogeneous Phase Effect of Smart Meta-Superconducting MgB ₂

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 MgB ₂ doped with six kinds of electroluminescent materials, such as YVO ₄: Eu ^{3 +} and Y ₂O ₃: Eu ^{3 +} flakes. Elemental mappings through energy dispersive spectroscopy (EDS) show that the inhomogeneous phase is comparatively uniformly dispersed around the 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 MgB ₂ is 2.0 wt%. The offset temperature (TCoff) of the sample doped with 2.0 wt% dopant A is 1.6 K higher than that of pure MgB ₂. The improvement in TCoff is likely related to the sizes, thickness, and EL intensity of the inhomogeneous phase of MgB ₂ smart meta-superconductor. This experiment provides a novel approach to enhance T_C.