Investigation of Hot Press and Cold Press Effects on Structural, Electrical and Magnetic Properties of Pyrene Added Bulk MgB2
Küçük Resim Yok
Tarih
2024
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this paper, the effects of hot pressing and cold pressing on the superconducting properties of pyrene (C16H10) added bulk MgB2 were compared. For this aim, the polycrystalline disk-shaped MgB2 samples with addition of 4 wt % C16H10 powder were fabricated by a pellet/closed tube method at 850 degrees C, after hot pressing at 200 degrees C and cold pressing. The XRD and SEM results showed that although a-lattice parameters reduce for both C16H10 added samples, the average crystallite size increases after cold pressing because of the accumulation and inhomogeneous distribution of C in the MgB2 structure while it reduces for the C16H10 added hot pressed sample. The resistivity measurements showed that the increment of electron scattering is higher for the C16H10 added cold pressed sample than that of the C16H10 added hot pressed one which shows relatively better grain connectivity, and the Tc values of the samples are not appreciably affected by the pressing conditions. From the magnetisation measurements the in-field J(c) values at 10 K and 5.5 T were obtained as 8.41 x 10(3) A/cm(2), 1.62 x 10(4) A/cm(2), 6.90 x 10(3) A/cm(2) and the Hirr values while J(c) = 100 A/cm(2) at 20 K were obtained as 5.99 T, 6.55 T and 6.19 T for the pure sample and the C16H10 added hot and cold pressed samples, respectively. The higher J(c )and H-irr values obtained for the C16H10 added hot pressed sample is because of the homogenous C substitution into MgB2 grains, as compatible with its lower Delta rho value, and thus increased flux pinning ability.
Açıklama
Anahtar Kelimeler
Superconductivity, MgB2, Hot pressing, Cold pressing, Pyrene, Resistivity
Kaynak
Brazilian Journal of Physics
WoS Q Değeri
N/A
Scopus Q Değeri
Q4
Cilt
54
Sayı
5
