Smart meta-superconductor MgB constructed by the dopant phase of luminescent nanocomposite.

On the basis of the idea that the injecting energy will improve the conditions for the formation of Cooper pairs, a smart meta-superconductor (SMSC) was prepared by doping luminescent nanocomposite YO:Eu/Ag in MgB. To improve the superconducting transition temperature (T) of the MgB-based superconductor, two types of YO:Eu/Ag, which has the strong luminescence characteristic, with different sizes were prepared and marked as m-YO:Eu/Ag and n-YO:Eu/Ag. MgB SMSC was prepared through an ex situ process. Results show that when the dopant content was fixed at 2.0 wt.%, the T of MgB SMSC increased initially then decreased with the increase in the Ag content in the dopant. When the Ag content is 5%, the T of MgB SMSC was 37.2-38.0 K, which was similar to that of pure MgB. Meanwhile, the T of MgB SMSC doped with n-YO:Eu/Ag increased initially then decreased basically with the increase in the content of n-YO:Eu/Ag, in which the Ag content is fixed at 5%. The T of MgB SMSC doped with 0.5 wt.% n-YO:Eu/Ag was 37.6-38.4 K, which was 0.4 K higher than that of pure MgB. It is thought that the doping luminescent nanocomposite into the superconductor is a new means to improve the T of SMSC.