Tailoring the microstructural and electromagnetic response of SPS-synthesized MgB2 through organic C15H12O2 additions

Abstract In this study, the microstructural, electrical, and electromagnetic properties of MgB 2 bulk superconductors modified with the organic additive of phenyl(3-phenyloxirane-2-yl)methane (C 15 H 12 O 2 ) were investigated. Pure and bulk MgB 2 samples doped with 0–20 wt% C 15 H 12 O 2 were produced by in situ Spark Plasma Sintering (SPS) at 850 °C, 50 MPa pressure, and 10 min. X-ray diffraction analyses showed that the hexagonal MgB 2 phase was predominantly preserved in all samples, with limited MgO formation observed at increasing addition rates. SEM analyses revealed that organic additive created controlled porosity and microstructural heterogeneity. Electrical measurements showed a limited decrease in the superconducting transition temperature and an increase in the normal-state resistivity in the doped samples. Magnetic characterization results revealed that the sample containing 15 wt% C 15 H 12 O 2 exhibited the highest critical current density and optimized pinning force at 20 K. Levitation force measurements performed under ZFC and FC conditions have shown a strong correlation between microstructure-derived pinning architecture and electromagnetic response. The results reveal that C 15 H 12 O 2 addition offers a suitable approach for effectively tuning the pinning and levitation properties of SPS-generated MgB 2 bulk superconductors.