نتایج جستجو برای: ابررسانای تکتایی

تعداد نتایج: 286  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه زنجان 1387

چکیده ندارد.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بوعلی سینا - دانشکده علوم پایه 1386

چکیده ندارد.

منحوش, ندا, موسوی قهفرخی, سید ابراهیم, کاظمی‌نژاد, ایرج,

In this paper, β-PbO nanoparticles were prepared by microwave irradiation. Then, the PbO nanoparticles with size of 32 nm were doped in the Bi2-xPbxSr2Ca2Cu4Oy superconductor with x = 0.0, 0.2, 0.4 and 0.6. The samples were synthesized by the standard solid state reaction method. The structural properties, microstructure and morphology of the samples have been studied by XRD and SEM. After synt...

زرگرشوشتری, مرتضی, کلانترهرمزی, راهیل, موسوی قهفرخی, سیدابراهیم ,

In this paper, Au nanoparticles are synthesized by solution method. The effect of these nanoparticles on the Bi1.6Pb0.4Sr2Ca2Cu3Oy superconductor properties has been investigated. The critical current density, activation energy and room temperature resistivity were measured by the standard four-probe method. The microstructure and morphology of samples have been studied by X-ray diffraction, Sc...

احمدوند, حسین, باقی, مرضیه, سلامتی, هادی, سهرابی, داوود, عبدالحسینی, اسماعیل, مرشدلو, تکتم, کاملی, پرویز,

Bi1.8Pb0.4Sr2-xBaxCa2.2Cu3Oy (x-0, 0.1, 0.2, 0.3) samples were prepared by a conventional solid state reaction method. The effect of Ba substitution at Sr site in Bi-2223 high-TC superconductors have been investigated by the XRD, SEM, dc electrical resistivity and ac susceptibility. XRD and SEM analysis indicated Ba substitution decreased temperature of 2223 phase formation. The highest 2223 ph...

طیب‌طاهر, محبوبه , فربد, منصور, کاظمی‌نژاد, ایرج,

This paper describes the details of synthesizing nano crystalline YBCO superconductor using a sol-gel combustion method and the effect of sol pH and sintering temperature on particle size was investigated. The sintering temperature was chosen 880°C and the samples were annealed at this temperature for 5 hours. The morphology and structure of the nano scale products were characterized by powder ...

باشی, مریم, بروغنی, آتنا, قربانی, شعبان‌رضا,

Fulx-pinning mechanism and activation energy of MgB2 doped with 10 wt % malic- acid has been investigated by measurement of critical current density and resistivity as a function of magnetic fields and temperatures. The field dependence of the critical current density, Jc(B), was analyzed within the collective pinning model. A crossover field, Bsb, from the single vortex to the small vortex bun...

دادمهر , وحید , صائب, فاطمه , فلاحتی , سمیه ,

 We fabricated YBa2Cu3-xMxO7- d (M=Ni, Fe) bulk samples, with stochiometric amount 0≤x≤0.045 by sol-gel method. The phase analysis and microstructure of specimens were examined by XRD and SEM. The electrical resistivity was measured using standard four probe technique for 77-300K. Investigation of XRD spectrum by MAUD shows Ni and Fe ions substitute in Cu(2) and Cu(1) site, respectively. Transi...

بتوندی , محمدرضا , زرگر شوشتری , مرتضی , فربد, منصور ,

  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...

سلامتی , هادی , سهرابی, داود , کاملی , پرویز ,

 In this study, the superconducting properties of Bi-2223/Ag wires, made by the PIT method have been studied. Powder samples were prepared using conventional solid state reaction method. After calcination, samples with different Ag percent (0, 5, 10, 15, 20, and 25) prepared and sintered at 830 °C. It was shown that Ag addition has not only affected the formation of the desired Bi-2223 phase an...

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