scholarly journals О возможности изготовления мостиков YBCO с совершенной поверхностью, критической температурой более 88 K и плотностью критического тока до 5·10-=SUP=-6-=/SUP=- A/cm-=SUP=-2-=/SUP=-

2020 ◽  
Vol 62 (9) ◽  
pp. 1398
Author(s):  
Д.В. Мастеров ◽  
С.А. Павлов ◽  
А.Е. Парафин ◽  
Е.В. Скороходов
Keyword(s):  
Critical Temperature ◽  
Surface Morphology ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Growth Process ◽  
Ybco Films ◽  
Basic Parameters ◽  
Critical Current Density Jc ◽  
Electrophysical Parameters

In the fabrication of YBCO structures by traditional methods, as a rule, some compromise is reached, namely, films with acceptable morphology are used, but with reduced electrophysical parameters. In this paper, it is shown that YBCO bridges up to 4 microns wide with perfect surface morphology, i.e. free from defects, with a critical current density Jc ≥ 3106 A/cm2 at a temperature T = 77 K and a critical temperature Tс ≥ 88 K. can be obtained using the preliminary topology mask method. Moreover, the perfect morphology of the bridge surface, the values of the critical current density and the critical temperature are preserved even after repeated (additional) deposition of the YBCO layer on the structure with the preliminary topology mask. Based on the results obtained in a series of fifteen samples, it is concluded that, in contrast to the electrophysical characteristics, it is not enough to fix the standard (basic) parameters of the growth process for the stable implementation of the perfect surface morphology of YBCO films.

Comparative Study of Thickness Dependence of Critical Current Density of Yba2Cu3O7–δ on (100) SrTiO3 and on Rolling-assisted Biaxially Textured Substrates

2002 ◽  
Vol 17 (7) ◽  
pp. 1750-1757 ◽  
Author(s):  
B. W. Kang ◽  
A. Goyal ◽  
D. F. Lee ◽  
J. E. Mathis ◽  
E. D. Specht ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Critical Current Density ◽  
Film Thickness ◽  
Comparative Study ◽  
Critical Current ◽  
Current Density ◽  
Pulsed Laser ◽  
Cube Texture ◽  
Laser Deposition ◽  
Ybco Films

We investigated the dependence of critical current density (Jc) on thickness of Yba2Cu3O7−δ (YBCO) films grown by pulsed laser deposition on (100) SrTiO3 (STO) and on rolling-assisted biaxially textured substrates (RABiTS). The thickness of YBCO films varied from 0.19 to 3 μm. The highest Jcs of 5.3 and 2.6 MA/cm2 at 77 K, self-field were obtained for 0.19-μm YBCO films on STO and RABiTS, respectively. Jc was found to decrease exponentially with YBCO thickness on both substrates. However, the results suggest different mechanisms are responsible for the Jc reduction in the two cases. On STO, growth of a-axis grains within c-axis films and broadening of the in-plane texture were observed in thick films. On RABiTS, degradation in cube texture as well as development of a porous surface morphology were found to correlate with film thickness.

High Critical Current Density in Ultrathin Ybco Films

1989 ◽  
Vol 169 ◽  
Author(s):  
X.X. Xi ◽  
W. Schauer ◽  
V. Windte ◽  
O. Meyer ◽  
G. Linker ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Thick Film ◽  
Critical Current ◽  
Field Dependence ◽  
Current Density ◽  
Weak Field ◽  
Zero Field ◽  
High Critical Current Density ◽  
Ybco Films ◽  
Critical Current Density Jc

AbstractMeasurements of the critical current density Jc for ultrathin YBa2Cu307‐X (YBCO) films are presented.A high Jc value at 77K in zero field of 2xl06A/cm2 was obtained in a 30nm thick film and even a 5nm thick film could carry a supercurrent of 3.5x105 A/cm2 at 4.2K in zero field. A very weak field‐dependence of Jc was observed when the field was in the (a,b) plane showing greatly depressed dissipation.

scholarly journals The Influence of Surface Morphology of Buffer Layer on the Critical Current Density in YBCO Coated Conductors

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jie Xiong ◽  
Yudong Xia ◽  
Fei Zhang ◽  
Yan Xue ◽  
Kai Hu ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Critical Current Density ◽  
Buffer Layer ◽  
Critical Current ◽  
Current Density ◽  
Coated Conductors ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Ybco Films ◽  
Surface Morphologies

1 μm-thickYBa2Cu3O7-δ(YBCO) films were grown on the Y2O3/yttria stabilized zirconia (YSZ)/CeO2buffer layers with different surface morphologies using direct-current sputtering. The critical current density (Jc) value of YBCO was 1.1 MA/cm2when the root mean square surface roughness (Rrms) of the buffer layer was 2.5 nm. As theRrmsof the buffer layer increased to 15 nm, theJcdecreased to 0.3 MA/cm2. X-ray diffraction and scanning electron microscopy showed the strong relevance of the evolution of the structure and surface morphologies of YBCO films with the buffer layer of differentRrms. A model was proposed to explain the influence of surface morphology on the superconducting properties of YBCO films.

Stoichiometric effects in epitaxial Ba2−xY1−yCu3−zO7−δ thin films on LaAlO3(100)

1990 ◽  
Vol 5 (12) ◽  
pp. 2797-2801 ◽  
Author(s):  
Douglas J. Carlson ◽  
Michael P. Siegal ◽  
Julia M. Phillips ◽  
T. H. Tiefel ◽  
J. H. Marshall
Keyword(s):  
Thin Films ◽  
Critical Temperature ◽  
Surface Morphology ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Superconducting Transition ◽  
Transition Width ◽  
Composition Control ◽  
Order Of Magnitude

Stoichiometric deviations of up to ±5% in Ba2YCu3O7−δ, thin films grown by coevaporation on LaAlO3(100) substrates are found to cause (1) a decrease of the critical current density (Jc) of up to an order of magnitude, (2) a depression of the critical temperature (Tc) and a broadening of the superconducting transition width (ΔT), (3) a deterioration of the surface morphology, and (4) a decrease in the crystallinity of the films. The data indicate that composition deviations of greater than ±1% result in degradation of film quality. These findings have significant implications for the degree of composition control required during deposition to produce films with optimized properties.

An all-field-range description of the critical current density in superconducting YBCO films

2011 ◽  
Vol 24 (10) ◽  
pp. 105020 ◽  
Author(s):  
I A Golovchanskiy ◽  
A V Pan ◽  
O V Shcherbakova ◽  
S A Fedoseev ◽  
S X Dou
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Field Range ◽  
Ybco Films

Studies on Development of MgB2 Superconductor with Improved In-Field Critical Current Density

2010 ◽  
Vol 117 ◽  
pp. 63-68 ◽  
Author(s):  
Krishnankutty Vinod ◽  
Syamaprasad Upendran
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Natural Material ◽  
Bulk Superconductor ◽  
Mgb2 Wires ◽  
Heating Method ◽  
Self Heating ◽  
Critical Current Density Jc ◽  
Powder In Tube

The present study focuses on the preparation of good quality MgB2 superconductor in bulk, wire/tape forms and on the improvement of in-field critical current density [JC(H)]. MgB2 bulk superconductor was prepared by a simple Powder-In-Sealed-Tube (PIST) method and MgB2 wires and tapes were prepared by the Powder-In-Tube (PIT) method. A novel electrical self-heating method was introduced for the preparation of Fe sheathed MgB2 wires and tapes. Burned Rice Husk (BRH), an inexpensive natural material is found to be one of the best additives for enhancing the in-field critical current density of MgB2. By selecting suitable combinations of additives a significant enhancement of the critical current density by 1-2 orders of magnitude were achieved for fields > 5 T, at 5-15 K.

scholarly journals Distinct doping dependence of critical temperature and critical current density in Ba1−xKxFe2As2 superconductor

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Dongjoon Song ◽  
Shigeyuki Ishida ◽  
Akira Iyo ◽  
Masamichi Nakajima ◽  
Jun-ichi Shimoyama ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Doping Dependence

Effect of Pulsed Magnetic Field Processing on MgB2 Superconductors

2007 ◽  
Vol 546-549 ◽  
pp. 2063-2066 ◽  
Author(s):  
W.X. Li ◽  
Ying Li ◽  
M.Y. Zhu ◽  
R.H. Chen ◽  
H.M. Jin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Pulsed Magnetic Field ◽  
Pinning Force ◽  
Critical Current Density Jc ◽  
Mgb2 Superconductors ◽  
Doped Mgb2 ◽  
Flux Pinning Force

Pulsed magnetic field was first employed in the study on MgB2 superconductors. Superconductivity properties and microstructures of Zn and SiC doped MgB2 were discussed in this paper. The superconductors showed different superconductivities after magnetic sintering. Critical current density and flux pinning force were relevant to the dopants properties in MgB2. Grains in the pulsed magnetic processed MgB2 matrix were smaller than those in the normal processed one. The refinement microstructures have caused the critical current density (Jc) anisotropy in both the Zn and SiC doped MgB2.

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