Critical Temperature of Smart Meta-superconducting MgB2

Enhancing the critical temperature (T (C) ) is important not only to widen the practical applications but also to expand the theories of superconductivity. Inspired by the meta-material structure, we designed a smart meta-superconductor consisting of MgB2 microparticles and Y2O3/Eu3+ nanorods. In the local electric field, Y2O3/Eu3+ nanorods generate an electroluminescence (EL) that can excite MgB2 particles, thereby improving the T (C) by strengthening the electron-phonon interaction. An MgB2-based superconductor doped with one of four dopants of different EL intensities was prepared by an ex situ process. Results showed that the T (C) of MgB2 doped with 2 wt% Y2O3, which is not an EL material, is 33.1 K. However, replacing Y2O3 with Y2O3/Eu3+II, which displays a strong EL intensity, can improve the T (C) by 2.8 to 35.9 K, which is even higher than that of pure MgB2. The significant increment in T (C) results from the EL exciting effect. Apart from EL intensity, the micromorphology and degree of dispersion of the dopants also affected the T (C) . This smart meta-superconductor provides a new method to increase T (C) .