| Yazarlar |
Prof. Dr. Özgür ÖZTÜRK
Abant İzzet Baysal Üniversitesi, Türkiye |
Tayfur Küçükömeroğlu
Karadeniz Teknik Üniversitesi, Türkiye |
|
Cabir Terzioğlu
Abant İzzet Baysal Üniversitesi, Türkiye |
| Özet |
| Undoped Bi-2223 samples were prepared using a conventional solid-state reaction method. Doping of Au in Bi-2223 was carried out by means of diffusion from an evaporated Au film on pellets. We have investigated the effect of Au diffusion and diffusion-annealing duration on the microstructure and superconducting properties of Au-doped samples by performing x-ray diffraction (XRD), scanning electron microscopy (SEM), dc resistivity and critical current density measurements. Gold diffusion in Bi1.8Pb0.35Sr 1.9Ca2.1Cu3Oy has been studied over the temperature range 500-800 °C using the technique of successive removal of thin layers and the measurements of lattice parameters from XRD patterns at room temperature. The diffusion doping of Bi-2223 by Au causes a significant increase of the lattice parameter c by about 0.19%. This observation is used for calculation of the Au diffusion coefficient in Bi-2223. The Au diffusion coefficient decreases as the diffusion-annealing temperature decreases. The temperature dependence of the Au diffusion coefficient in the range 500-800 °C is described by the relation D ≤ 4.4 × 10-4exp(-1. 08eV/kBT). Au doping of the sample increased the critical transition temperature and the critical current density from 100 0.2 to 104 0.2K and from 40 to 125Acm-2, in comparison with those of undoped samples. The critical transition temperature and critical current density of Au-doped samples increased with increasing diffusion-annealing time from 10 to 50h. Au doping of the sample also improved the surface morphology and increased the high-T c phase ratio. The possible reasons for the observed improvement in superconducting properties of the samples due to Au diffusion are discussed. © IOP Publishing Ltd. |
| Anahtar Kelimeler |
| Makale Türü | Özgün Makale |
| Makale Alt Türü | SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale |
| Dergi Adı | Journal of Phys.- Condensed Matter |
| Dergi Tarandığı Indeksler | SCI |
| Makale Dili | İngilizce |
| Basım Tarihi | 07-2007 |
| Cilt No | 19 |
| Sayı | 34 |
| Sayfalar | 34 / 44 |
