Doping Effect on Partial-Melting of HgxBa2Ca2Cu3Re0.2Oy Filament
We have studied the fabrication of filamentary Fig system superconductor using a solution spinning method with Re addition. A controlled vapor/solid reaction process is necessary for preparing Hg-based superconductor by this method. As the F-doping resulted in a dense liquidus texture, F and Cl doping effects on partial-melting of filamentary Hg x Ba2Ca2Cu3Re0.2O y superconductor are examined to enhance the J c and to reduce the inciting temperature. A filamentary Ba2Ca2Cu3Re0.2O y precursor was spun by a solution spinning method and partially melted in an evacuated quartz tube with a pellet as a reactor. Hg1Ba1.8Ca2Cu3Re0.2(BaF2)0.2O y , Hg0.8Ba1.8Ca2Cu3Re0.2(BaF2)0.2O y , Hg1Ba2Ca2Cu2.8Re0.2(CuF2)0.2O y , Hg0.925Ba2Ca2Cu3Re0.2(HgCl2)0.075O y and Hg0.8Ba1.8Ca2Cu3Re0.2(BaF2)0.2(HgCl2)0.03O y pellets were prepared by a two-step solid state reaction method.
The partial-inelting temperature of the filamentary sample reacted with Hg1Ba2Ca2Cu2.8Re0.2(CuF2)0.2O y pellet was lower than others. The texture of the filamentary sample was dependent on the vaporizing materials. The J c of the sample was enhanced by post-annealing up to 350 °C in O2 flow. By controlling the heating condition, a high J c value more than 104 A/cm2 at 77 K and 0 T was attained for both F and Cl doped sample.
KeywordsVapor Source Doping Source Evacuate Quartz Tube Ammonium Perrhenate Detail Phase Diagram
- 2.R. L. Meng, H. Hickey, Y. Q. Wang, Y. Y. Sun, L. Gao, Y. Y. Xue and C. W. Chu, Processing of highly oriented (Hgi_Jtex)Ba2Ca2Cu30s+y tape with x-0.1, Appl.Phys.Lett. 68: 3177 (1996).Google Scholar
- 5.T. Goto, Partial melting of F-doped 11g,Ba2Ca2Cu3Reo_20y filament. Physica C. to be published.Google Scholar
- 7.T. Goto, Effect of F-doping in solution-spun 11g.,Ha,Ca2Cu3Reo 20,E Filament. Advanc. in Superconductivity XIV. to be published.Google Scholar