Homovalent Ho/Bi substitution effect on characteristic properties of Bi-2212 superconducting ceramics
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Tarih
2021
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In the current work, the effect of trivalent Ho/Bi partial replacement on the fundamental characteristic features such as the general crystallinity quality quantities, dc electrical resistivity, superconducting, degree of granularity, strength quality of intra- and inter-grain boundary couplings in the oxygen-deficit multi-layered perovskite-based Bi2.1Sr2.0Ca1.1Cu2.0Oy (Bi-2212) superconducting ceramics is examined by powder X-ray diffraction (XRD), temperature-dependent electrical resistivity (rho-T), and Archimedes water displacement methods. The polycrystalline Bi2.1-xHoxSr2.0Ca1.1Cu2.0Oy compounds are produced by the conventional ceramic method within the molecular ratio intervals 0.00 <= x <= 0.30. All the experimental findings show that the trivalent holmium (Ho3+) impurities are successfully substituted by the bismuth (Bi3+) particles in the Bi-2212 crystal system. Besides, the optimum holmium concentration for the bulk Bi-2212 superconducting ceramics is recorded to be x = 0.01. XRD results indicate that the Bi-2212 material prepared by the optimum Ho/Bi substitution possesses the maximum average crystallite size (60 nm), Bi-2223 superconducting phase volume fraction (33.48%), c-axis length (32.55 angstrom), and Lotgering index (0.48) parameters. In this respect, the best sample with particle distributions well linked each other has the maximum bulk density value of 6.04 g/cm(3) and minimum degree of granularity of 4.13%. It is obvious that the optimum (excess) Ho/Bi partial substitution supports the enhancement in the density (granular structure nature) of Bi-2212 compound. Moreover, dc electrical resistivity measurement results show that the optimum homovalent Ho/Bi partial substitution in the Bi-2212 superconducting matrix leads to increase the homogeneities in the oxidation state of superconducting grains and especially densities of active and effective electronic states (DOS) at Fermi energy level. To sum up, this study indicates that the optimum trivalent Ho/Bi partial substitution increases the usage of Bi-2212 superconducting materials in much more application fields.
Açıklama
Anahtar Kelimeler
Kaynak
Journal of Materials Science-Materials In Electronics
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
32
Sayı
24
