EDXRF measurements on gold diffusion-doped Bi1.8Pb0.35Sr1.9Ca2.1Cu3Oy
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Dosyalar
Tarih
2008
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier B.V. All
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Gold (Au) diffusion in superconducting Bi1.8Pb0.35Sr1.9Ca2.1Cu3Oy was investigated over the temperature range 500-800 degrees C by the energy dispersive X-ray fluorescence (EDXRF) technique. It is found that the Au diffusion coefficient decreases as the diffusion-annealing temperature decreases. The temperature dependences of Au diffusion coefficient in grains and over grain boundaries are described by the relations D-1 = 6.7 x 10(-5)exp(-1.19 eV/k(B)T) and D-2 = 9.7 x 10(-4)exp(- 1.09 eV/k(B)T), respectively. The diffusion doping of Bi-2223 by Au causes a significant increase of the lattice parameter c by about 0.19%. For the Au-diffused samples, dc electrical resistivity and transport critical cur-rent density measurements indicated the critical transition temperature increased from 100 to 104 K and the critical current density increased from 40 to 125 A cm(-2), in comparison with those of undoped samples. From scanning electron microscope (SEM) and X-ray diffraction (XRD) measurements it is observed that Au doping of the sample also improved the surface morphology and increased the ratio of the high-T-c phase to the low-T-c phase. The possible reasons for the observed improvement in microstructure and superconducting properties of the samples due to Au diffusion are also discussed. (C) 2008 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Au Diffusion, Diffusion Coefficient, Activation Energy, Transition Temperature
Kaynak
Physica B-Condensed Matter
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
403
Sayı
18
