Effect of annealing conditions on the superconducting properties of nano-sized metallic Au-added Bi1.8Sr2Au0.2Ca1.1Cu2.1Oy(Bi-2212) ceramics
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Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, the effects of annealing process on the phase formation and electrical and magnetic properties of nano-sized metallic Au-added Bi-2212 ceramics have been investigated. The Bi(1.8)Sr(2)Au(0.2)Ca(1.1)Cu(2.1)O(y)includingx = 0.2 Au content as starting composition was chosen due to the improved transport properties in the Bi-2212 system, as known in the literature. The samples for the post-annealing technique were exposed at different dwell times (10 m, 30 m, 1 h, and 2.5 h) at a fixed temperature of 870 degrees C after the application of normal heat treatment of 850 degrees C for 120 h. The XRD diagrams clearly indicate that a significant part of the phases in all the samples belongs to Bi-2212 phase. SEM results show that all the samples have randomly oriented grain forms as the main characteristic of applied solid-state method. In all cases, the post-annealed samples showed better superconducting properties of Bi-2212 phase, indicating that the increases in the dwell time positively affect its granular polycrystalline character such as inter-connectivity of the grains, the nucleation, and growth of the Bi-2212 phase. Moreover, the sample with dwell time of 2.5 h at 870 degrees C reveals significant enhancement in theM-Hloops compared to the sample with less dwell time, despite the fact that the Bi-2212 phase can easily decompose into secondary phases such as Cu-free and Bi-free due to thermodynamic instabilities of Bi-2212 at temperatures above 860 degrees C. Finally, the intragranular critical current density values (J(c)) have been obtained by using the data from M-H measurements according to the critical Bean model. It has been found that theJ(c)value (16.5 x 10(4) A/cm(2)in 0.15 T at 15 K) of the sample in the dwell time of 2.5 h at 870 degrees C is higher than that of the sample (13.4 x 10(4) A/cm(2)in 0.15 T at 10 K) with the same starting composition reported in the literature.
Açıklama
Anahtar Kelimeler
Artificial Pinning Centers, Magnetic-Properties, Thin-Films, Phase-Formation, Growth Speed, T-C, Temperature, Ag, Bi, Substitution
Kaynak
Journal of Materials Science-Materials in Electronics
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
31
Sayı
14
