AC susceptibility analysis on MgB2 bulk and Ti-sheathed wire superconductors
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Dosyalar
Tarih
2014
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Sci Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
We report a comparative study for bulk MgB2 superconductors and monofilamentary Ti/MgB2 wires as functions of the boron powder purity, average particle size of magnesium, and applied pressure. The structural and magnetic characterizations of the bulk samples were performed by means of XRD and AC susceptibility measurements, respectively. We found that the applied pressure did not cause any significant change on the onset transition temperature T-c,T-onset and transition width. This is also confirmed by the calculation of the lattice parameters. On the other hand, T-c,T-onset values were measured as 37.3 K, 38.0 K, and 38.6 K for the samples prepared from the precursor boron powders with purities of 95.2%, >= 95%, and >98%, respectively. However Mg-particle size (Mg1: AlfaAesar Mg powder, avg. par. size: -325 mesh, purity: 99.8%; Mg2: SigmaAldrich Mg powder, avg. par. size: 20-230 mesh, purity: 98%) did not affect the T-c,T-onset but increasing the Mg particle size caused a significant broadening at the superconducting transition width for all precursor boron powder purity levels. Magnetization measurements showed that the critical current density of Ti/MgB2 wire prepared from AlfaAesar Mg powder (avg. par. size: -325 mesh) and Aldrich B powder (amorphous, purity >= 95%) is greater than that of prepared by SigmaAldrich Mg powder (avg. par. size: 20-230 mesh) and Pavezyum B powder (amorphous, avg. par. size: 0,3 mu m (max), purity > 98%) as 2.6 x 10(5) A/cm(2) and 1.4 x 10(5) A/cm(2) at T = 10 K and mu H-0 = 0.5 T, respectively. In addition, SigmaAldrich Mg and Pavezyum B wire sample has a lower pinning force, F-p, value at each temperature. (C) 2014 Elsevier Ltd. All rights reserved.
Açıklama
7th Asian Conference on Superconductivity and Cryogenics (ACASC) -- OCT 23-25, 2013 -- Urgup, TURKEY
Anahtar Kelimeler
MgB2 Bulk and Wire, Boron Powder, XRD, AC Susceptibility, Magnetization Measurements
Kaynak
Cryogenics
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
63
