Decoupling Substitution and Connectivity in Chalcone-Doped MgB2 via Spark Plasma Sintering
Journal of the American Ceramic Society, cilt.109, sa.7, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 109 Sayı: 7
- Basım Tarihi: 2026
- Doi Numarası: 10.1111/jace.71000
- Dergi Adı: Journal of the American Ceramic Society
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Periodicals Index Online, Applied Science & Technology Source, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: critical current density, Dew–Hughes model, flux pinning, MgB2 bulk superconductor, organic carbon source, spark plasma sintering
- Hakkari Üniversitesi Adresli: Evet
Özet
Pure and C15H12O (chalcone)-doped MgB2 bulk superconductors were synthesized via spark plasma sintering (SPS) at 850°C under 50 MPa. The influence of organic doping on structural, electrical, and magnetic properties was systematically investigated. Phase analysis via XRD and Tc measurements confirmed successful carbon substitution into the MgB2 lattice, evidenced by an a-axis contraction. Magnetic characterization at 20 K revealed that low doping levels (5 wt%) enhance critical current density (Jc) and pinning force (Fp) by forming effective nanoscale pinning centers at grain boundaries. However, higher doping concentrations significantly degrade performance, particularly in high magnetic fields. This degradation is attributed to reduced grain-to-grain connectivity caused by increased porosity and the accumulation of non-superconducting secondary phases (MgO and amorphous carbon) resulting from the organic precursor's decomposition. Dew–Hughes analysis indicated a shift in pinning behavior, reflecting a trade-off between enhanced flux pinning and compromised connectivity. The results highlight the critical importance of balancing lattice substitution and inter-grain binding in organic-doped MgB2 systems, demonstrating the potential of chalcone as an effective carbon source for optimized superconducting applications.