Formation of high-field pinning centers in superconducting MgB2 wires by using high hot isostatic pressure process
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Dosyalar
Tarih
2017
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
This paper demonstrates the effects of hot isostatic pressure (HIP) on the structure and transport critical parameters of in situ MgB2 wires without a barrier. Our results show that only HIP and nano-boron allow the formation of more high-field pinning centers, which lead to the increase in critical current density (J (c)) at high applied magnetic fields. Nano-boron and annealing at a low pressure increase the J (c) in the low magnetic field. This indicates that nano-particles create more high-field pinning centers. In addition, the results show that nano-boron improves the connection between the grains. Scanning electron microscope results show that HIP increases the reaction rate between Mg and B, density, and homogeneity of the MgB2 material. Additionally, HIP allows to create a structure with small grains and voids and eliminates the significance of the number of voids. High isostatic pressure allows to obtain high J (c) of 10 A/mm(2) (at 4.2 K) in 10 T and increases irreversible magnetic field (B (irr)) and upper critical field (B (c2)). Measurements show that these wires have high critical temperature of 37 K.
Açıklama
Anahtar Kelimeler
MgB2 Wires, High Fields Pinning Centers, Critical Current Density
Kaynak
Journal Of Superconductivity And Novel Magnetism
WoS Q Değeri
Q4
Scopus Q Değeri
Q3
Cilt
30
Sayı
12
