Critical Current Density and Meissner Effect of Smart Meta-Superconductor MgB₂ and Bi(Pb)SrCaCuO

The smart meta-superconductor MgB₂ and Bi(Pb)SrCaCuO increase the superconducting transition temperature (T_C), but the changes in the transport critical current density (J_C) and Meissner effect are still unknown. Here, we investigated the J_C and Meissner effect of smart meta-superconductor MgB₂ and Bi(Pb)SrCaCuO. The use of the standard four-probe method shows that Y₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺+Ag inhomogeneous phase significantly increase the J_C, and J_C decreases to a minimum value at a higher temperature. The Meissner effect was measured by direct current magnetization. The doping of Y₂O₃:Eu³⁺ and Y₂O₃:Eu³⁺+Ag luminescent inhomogeneous phase causes a Meissner effect of MgB₂ and Bi(Pb)SrCaCuO at a higher temperature, while the non-luminescent dopant reduces the temperature at which samples have Meissner effect. The introduction of luminescent inhomogeneous phase in conventional MgB₂ and copper oxide high-temperature Bi(Pb)SrCaCuO superconductor increases the T_C and J_C, and Meissner effect is exerted at higher temperature. Therefore, smart meta-superconductivity is suitable for conventional and copper oxide high-temperature superconductors.