A smart meta-superconductor Bi(Pb)SrCaCuO (B(P)SCCO) may increase the critical transition temperature (T_C) of B(P)SCCO by electroluminescence (EL) energy injection of inhomogeneous phases. However, the increase amplitude ΔT_C ($\mathsf{\Delta }{T}_C=T_C-T_{C,pure}$) of T_C is relatively small. In this study, a smart meta-superconductor B(P)SCCO with different matrix sizes was designed. Three kinds of raw materials with different particle sizes were used, and different series of Y₂O₃:Sm³⁺, Y₂O₃, Y₂O₃:Eu³⁺, and Y₂O₃:Eu³⁺+Ag-doped samples and pure B(P)SCCO were prepared. Results indicated that the T_C of the Y₂O₃ or Y₂O₃:Sm³⁺ non-luminescent dopant doping sample is lower than that of pure B(P)SCCO. However, the T_C of the Y₂O₃:Eu³⁺+Ag or Y₂O₃:Eu³⁺ luminescent inhomogeneous phase doping sample is higher than that of pure B(P)SCCO. With the decrease of the raw material particle size from 30 to 5 μm, the particle size of the B(P)SCCO superconducting matrix in the prepared samples decreases, and the doping content of the Y₂O₃:Eu³⁺+Ag or Y₂O₃:Eu³⁺ increases from 0.2% to 0.4%. Meanwhile, the increase of the inhomogeneous phase content enhances the ΔT_C. When the particle size of raw material is 5 μm, the doping concentration of the luminescent inhomogeneous phase can be increased to 0.4%. At this time, the zero-resistance temperature and onset transition temperature of the Y₂O₃:Eu³⁺+Ag doped sample are 4 and 6.3 K higher than those of pure B(P)SCCO, respectively.

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.

Improving the critical transition temperature (TC) of Bi(Pb)SrCaCuO (B(P)SCCO) high-temperature superconductors is important, however, considerable challenges exist. In this study, on the basis of the metamaterial structure and the idea that the injecting energy will promote the formation of Cooper pairs, a smart meta-superconductor B(P)SCCO consisting of B(P)SCCO microparticles and Y2O3:Eu3++Ag or Y2O3:Eu3+ luminophor was designed. In the applied electric field, the Y2O3:Eu3++Ag or Y2O3:Eu3+ luminophor generates an electroluminescence (EL), thereby promoting the TC via EL energy injection. A series of Y2O3:Eu3++Ag topological luminophor-doped B(P)SCCO samples was prepared. Results showed that Y2O3:Eu3++Ag was dispersed around B(P)SCCO particles, forming a metastructure. Accordingly, the onset transition temperature (T_(C,on)) and zero resistance transition temperature (T_(C,0)) of B(P)SCCO increased. Meanwhile, the B(P)SCCO sample doped with 0.2 wt% Y2O3 or Y2O3:Sm3+ nonluminous inhomogeneous phase was also prepared to further prove the influence of EL on the T_C rather than the rare earth effect. Results indicated that the TC of the Y2O3 or Y2O3:Sm3+ doping sample decreased. However, the TC of the 0.2 wt% Y2O3:Eu3++Ag or Y2O3:Eu3+ luminophor-doped sample improved. This outcome further demonstrated that the smart metastructure method can improve the TC of B(P)SCCO.

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 inhomogeneous phase of luminescent nanocomposite Y2O3:Eu3+/Ag, which has the strong luminescence characteristic, in MgB2 to improve the superconducting transition temperature (TC) of the MgB2-based superconductor. Two types of Y2O3:Eu3+/Ag with different sizes were prepared and marked as m-Y2O3:Eu3+/Ag and nY2O3:Eu3+/Ag. MgB2 SMSC was prepared through an ex situ process. Results show that when the inhomogeneous phase content was fixed at 2.0 wt.%, the TC of MgB2 SMSC increased initially then decreased with the increase in the Ag content in the dopant. When the Ag content accounted for 5 wt.% of the inhomogeneous phase weight, the TC of MgB2 SMSC was 37.2-38.0 K, which was similar to that of pure MgB2. Meanwhile, the TC of MgB2 SMSC doped with n-Y2O3:Eu3+/Ag increased initially then decreased basically with the increase in the content of n-Y2O3:Eu3+/Ag, in which Ag accounted for 5 wt.% of the inhomogeneous phase. The TC of MgB2 SMSC doped with 0.5 wt.% n-Y2O3:Eu3+/Ag was 37.6-38.4 K, which was 0.4 K higher than that of pure MgB2. It is thought that the doping inhomogeneous phase of luminescent nanocomposite into the superconductor is a new means to improve the TC of SMSC.