Influence of coronene addition on some superconducting properties of bulk MgB2
Küçük Resim Yok
Tarih
2018
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer New York LLC
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study reports the effect of coronene (C24H12) addition on some superconducting properties such as critical temperature (Tc), critical current density (Jc), flux pinning force density (Fp), irreversibility field (Hirr), upper critical magnetic field (Hc2), and activation energy (U0), of bulk MgB2 superconductor by means of magnetisation and magnetoresistivity measurements. Disk-shaped polycrystalline MgB2 samples with varying C24H12 contents of 0, 2, 4, 6, 8, 10 wt%, were produced at 850 °C in Ar atmosphere. The obtained results show an increase in field-Jc values at 10 and 20 K resulting from the strengthened flux pinning, and a decrease in critical temperature (Tc) because of C substitution into MgB2 lattice, with increasing amount of C24H12 powder. The Hc2(0) and Hirr(0) values are respectively found as 144, 181, 172 kOe, and 128, 161, 145 kOe for pure, 4 wt% and 10 wt% C24H12 added samples. The U0 depending on the magnetic field curves were plotted using thermally activated flux flow model. The maximum U0 values are respectively obtained as 0.20, 0.23 and 0.12 eV at 30 kOe for pure, 4 wt% and 10 wt% C24H12 added samples. As a result, the superconducting properties of bulk MgB2 at high fields was improved using C24H12, active carbon source addition, because of the presence of uniformly dispersed C particles with nanometer order of magnitude, and acting as effective pinning centres in MgB2 structure. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Açıklama
Anahtar Kelimeler
Activation energy, Flux pinning, Magnetic fields, Technetium compounds, Temperature, Active carbon source, Bulk MgB2 superconductors, Critical temperatures, Flux pinning force, Irreversibility fields, Superconducting properties, Thermally activated, Upper critical magnetic fields, Magnesium compounds, Activation energy, Flux pinning, Magnetic fields, Technetium compounds, Temperature, Active carbon source, Bulk MgB2 superconductors, Critical temperatures, Flux pinning force, Irreversibility fields, Superconducting properties, Thermally activated, Upper critical magnetic fields, Magnesium compounds
Kaynak
Journal of Materials Science: Materials in Electronics
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
29
Sayı
20
