Microstructural and magneto-transport properties of Bi1.6Pb0.4Sr2Ca1-xGdxCu2O8+delta superconducting ceramics
Yükleniyor...
Dosyalar
Tarih
2017
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study aims to investigate the effect of Gd doping on the phase formation, microstructure, transport and magnetic properties of the Bi(Pb)-2212 system. A series of superconducting bulks with a nominal composition of Bi1.6Pb0.4Sr2Ca1-xGdxCu2O8+delta with x= 0, 0.05, 0.10 and 0.15 are synthesized by the solid state synthesis route. The formed samples are characterized by means of X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), electrical transport and magnetic measurements. The experiment results reveal that all the samples doped are composed of Bi-2212 phase and traces of Bi-2201 secondary phase when compared to the undoped sample. The refinement of cell parameters shows that the doping reduces the cell volume of the samples. The texture degree decreases with doping while the degree of orthorhombicity increases. Quantitative EDS analysis confirms that Gd atoms are successfully introduced into crystalline structure. The SEM micrographs show randomly distributed grains with a flake-like shape. The highest value of onset critical transition temperatures is obtained for x= 0.10 and is about 90.22 K, which correlates well with the observed slope of resistivity and the hole concentration of the CuO2 layers. Magnetic hysteresis loops suggest that the diamagnetism, remanant magnetization and lower critical field are better for x= 0.10. Based on the enhancements of both grain boundary weak-links and flux pinning centers, improvement of the critical current densities and flux pinning density is obtained with this kind of doping.
Açıklama
Anahtar Kelimeler
Bi-2212, HTSC, Critical Current Density, Hysteresis Loops, Flux Pinning
Kaynak
Physica B-Condensed Matter
WoS Q Değeri
Q3
Scopus Q Değeri
Cilt
505
