ذرات y2bacuo5به عنوان فاز ثانویه ای که در فرآیندهای ذوبی ساخت ابررسانای yba2cu3o7-? در حین تولید ابررسانا به وجود می آیند، نقش مهمی در بهبود خواص ابررسانا از جمله خواص مکانیکی و افزایش چگالی جریان بحرانی آن دارند. در این تحقیق از روش سل-ژل برای ساخت نانوذرات y2bacuo5 استفاده شده است و به دلیل این که در این روش عوامل زیادی بر اندازه ذرات موثرند برای کاهش تعداد آزمایشها و در نتیجه کاهش زمان و هزی...

  The objective of this work is to investigate the effect of Ag nanoparticles as the flux pinning centers. Ag nanoparticles with different particle sizes from 30 to 1000 nm were prepared through the chemical reduction of AgNO3 in an alcohol solution. Then, samples of YBa2Cu3O7-δ superconductors were doped by 1 and 2 weight percentage of Ag nanoparticles with different sizes. Samples were charac...

In this research, YBa2Cu3O7-d (0 < d < 1) nanocrystalite superconductor was prepared by mechanochemical alloying method. We synthesized YBa2Cu3O7-d via mixing the BaCO3, Y2O3, CuO powders and milling in SPEX 8000 for 5h with weight ratio of ball to powder 10:1 and steel balls of 11mm diameter, followed by heating for 4h at 850 ˚C. The superconductor phase formation process was completed with si...

Twinning is one of the main mechanisms of plastic deformation in crystals and its effect on the empirical properties has been important in materials science. Twin boundaries have been proved to be effective flux pinning centers in YBCO that increasing the critical current density. High-temperature superconductor YBa2Cu3O7-x (YBCO) nanoparticles were prepared by solid state alloying method. The ...

Electrospinning is one of the most feasible techniques for producing nanoceramic fibers. In this paper, YBa2Cu3O7-δ (YBCO) superconductor nanofibers synthesized using electrospinning. The first step was preparation of a composite that is formed by mixing yttrium, barium, and copper acetates with different percent of polyvinyl alcohol (PVA). Then, the composite polymer has been electrospun to pr...

In this paper, the Y1-xCdxBa2Cu3O7-δ superconductor with x=0, 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5 are prepared using the solid state method and the structure, electrical resistance, critical current density and critical temperature of it, have been studied. The results show that these doping do not affect so much on the structure and lattice parameters. The electrical resistance of samples incr...

 In this paper the effect of ammonium hydroxide addition to the solution of metallic oxide on sol gel preparation process of YBCO is studied with differential thermal analysis, thermal graviometry and X-ray diffraction. Two samples with and without ammonium hydroxide. Ammonium hydroxide prevents both barium nitrate precipitate during the gel preparation and also unwanted reaction as well as inc...