Yazarlar
- Erdem, O.(1)
- Erdem, Özge(1)
Yayınlar
- MakaleYalnız künye2024Scopus SJRQ3Comparison of Superconducting Properties of Bulk MgB2 Samples with Pyrene Additive Produced by B Powder and C encapsulated B Powder
Erdem, Özge
In this paper, the advantages and disadvantages of using B powder and C encapsulated B powder as a precursor during the production process of MgB2 with the addition of pyrene (C16H10) were investigated. Two MgB2 bulk samples with the addition of 10 wt % C16H10 of 1 g MgB2 were produced by the in-situ method using B powder and C encapsulated B powder. The C encapsulated B powder as a precursor was prepared by adding 10% C16H10 as a C source. From XRD and SEM analysis, a greater increase in MgO phase and a greater decrease in a-lattice parameter were observed for the sample produced with B, compared to the sample produced with C encapsulated B. The curves of critical current density (Jc) at 5 K showed a similar character for both samples. The Jc values at 5 K in self field were respectively obtained as 1.52 × 105 A/cm2 and 1.90 × 105 A/cm2 for the samples produced by B and C encapsulated B. The decrement ratio of in-field Jc at 20 K was less affected by increasing magnetic field for the sample produced using C encapsulated B due to the relatively higher increase in the irreversibility field (Hirr) and the upper critical magnetic field (Hc2) values. The Jc values at 20 K and 3 T were respectively determined as 1.49 × 104 A/cm2 and 1.93 × 104 A/cm2 for the samples produced with B and C encapsulated B.
AtıfScopus2WoS2OpenAlex2
İncele - MakaleAçık Erişim2024Scopus SJRQ3Investigation of Hot Press and Cold Press Effects on Structural, Electrical and Magnetic Properties of Pyrene Added Bulk MgB2
Erdem, O.
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 °C, after hot pressing at 200 °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 Jc values at 10 K and 5.5 T were obtained as 8.41 × 103 A/cm2, 1.62 × 104 A/cm2, 6.90 × 103 A/cm2 and the Hirr values while Jc = 100 A/cm2 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 Jc and Hirr values obtained for the C16H10 added hot pressed sample is because of the homogenous C substitution into MgB2 grains, as compatible with its lower Δρ value, and thus increased flux pinning ability.