Improving the Critical Temperature of MgB₂ Superconducting Metamaterials Induced by Electroluminescence

The MgB₂ superconductor was doped with electroluminescent Y₂O₃:Eu, to synthesise a superconducting metamaterial. The temperature dependence of the resistivity of the superconductor indicates that the critical temperature (T_C) of samples decreases when increasing the amount of doped Y ₂O₃ nanorods, due to impurity (Y ₂O₃, MgO and YB ₄). However, the T_C of the samples increase with increasing amount of doped Y ₂O₃:Eu ³⁺ nanorods, which are opposite to doped Y ₂O₃ nanorods. Moreover, the transition temperature of the sample doped with 8 wt % Y ₂O₃:Eu ³⁺nanorods is higher than those of doped and pure MgB ₂. The T_C of the sample doped with 8 wt % Y ₂O₃:Eu ³⁺ nanorods is 1.15 K higher than that of the sample doped with 8 wt % Y ₂O₃. The T_C of sample doped with 8 wt% Y ₂O₃:Eu ³⁺ is 0.4 K higher than that of pure MgB ₂. Results indicate that doping electroluminescent materials into MgB ₂ increases the transition temperature; this novel strategy may also be applicable to other superconductors.