Growth mechanism of Ag-foil-based artificially superconducting joints of YBa2Cu3O7 monoliths

2006 ◽  
Vol 21 (10) ◽  
pp. 2534-2541 ◽  
Author(s):  
S. Iliescu ◽  
X. Granados ◽  
T. Puig ◽  
X. Obradors

A new method was developed allowing large superconducting YBa2Cu3O7 (YBCO) monoliths having complex shapes to be obtained. This method consists of joining two or more YBCO monoliths, and it is based on the interfacial melting induced by metallic Ag thin foils inserted between YBCO pellets. Studies of the microstructure and the superconducting properties of the joints obtained by using this technology have shown that a perfect interface can be obtained without agglomerations of non-superconducting phases and with a critical current density as high as that of the original blocks. No evidence of Ag precipitates was detected either at the interface or into the YBCO solid matrix, suggesting a migration of Ag. For a better understanding of the interface growth mechanism, we studied the influence of the cooling rate. The knowledge on the Ag diffusion process has enabled us to propose a model for the growth mechanism of the YBCO/Ag/YBCO interfaces.

2011 ◽  
Vol 324 ◽  
pp. 241-244 ◽  
Author(s):  
R. Mawassi ◽  
R. Awad ◽  
Mohamad Roumie ◽  
M. Kork ◽  
I. Hassan

The major limitation of Bi-system superconductor applications is the intergrain weak links and weak flux pinning capability producing low critical current density of the Bibased phases. In order to enhance these characteristics and other superconducting properties, effective flux pinning centers are introduced into high temperature superconductors. In this work, different weight percentages of ZnO nano oxide were introduced at the final stage of the Bi1.8Pb0.4Sr2Ca2Cu3O10-y superconductor preparation process. Phase characterization was completed by X-ray diffraction (XRD). Exact constitution of the samples was determined using particle induced X-ray emission (PIXE). Granular and microstructure were investigated using scanning electron microscopy (SEM). Electrical resistivity as function of the temperature was carried to evaluate the relative performance of samples, and finally, E-J characteristic curves were obtained at 77K. Using 0.4 ZnO weight percentage, the electrical and granular properties were greatly enhanced, indicating more efficient pinning mechanisms. A critical current density of 949 A/cm2 was obtained which represents more than twice the value obtained for the pure sample (Jc= 445 A/cm2).


2017 ◽  
Vol 891 ◽  
pp. 483-488 ◽  
Author(s):  
Daniela Volochová ◽  
Vitaliy Antal ◽  
Jozef Kováč ◽  
Pavel Diko

The influence of Sm addition on the microstructure and superconducting properties of Y-Ba-Cu-O (YBCO) bulk superconductors has been studied. Precursor powders YBa2Cu3O7-δ (Y-123), Y2O3 and CeO2 were enriched with different amounts of SmBa2Cu3Oy (Sm-123) or Sm2O3 powders with the aim to increase critical current density, Jc,by introducing additional pinning centers. YBCO bulk superconductors with SmBa2Cu3Oy (Y123-Sm) or Sm2O3 (Y123-SmO) powder addition were prepared by the optimized top seeded melt growth process in the form of single grains. Microstructure analysis revealed that Sm2O3 addition leads to a higher amount of smaller Y2BaCuO5 (Y-211) particles, what is related to high critical current densities (Jc ~ 7 x 104 A/cm2) of the YBCO samples with Sm2O3 addition in low magnetic fields. The effect of Sm addition in the form of SmBa2Cu3Oy as well as Sm2O3 powder on Y2BaCuO5 particle size, critical temperature, Tc, and critical current density, Jc, is reported.


1989 ◽  
Vol 25 (2) ◽  
pp. 2180-2183 ◽  
Author(s):  
N. Sadakata ◽  
M. Sugimoto ◽  
O. Kohno ◽  
K. Tachikawa

2015 ◽  
Vol 1107 ◽  
pp. 601-605
Author(s):  
S.A. Senawi ◽  
H. Azhan ◽  
W.N.F.W. Zainal ◽  
W.A.W. Razali ◽  
A. Nazree ◽  
...  

This paper reports on the properties of YBa2Cu3Od (Y123) and YCaBa4Cu6Oy (Y146) with non-porous and porous structures. The relationship between calcium doping and critical temperature (Tc) was studied to determine the optimal superconducting properties. A series of heating and grinding via solid state reaction method was used to fabricate the ceramic materials. The electrical properties were investigated via critical temperature, TC and critical current density, JC using the resistivity measurement system (RMS). Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were used to analyze the material morphology and structure, respectively. The orthorhombicity increased due to less porosity of the samples. The calcium presence partially replaced larger Ba(II) site and degraded orthorhombicity. The highest critical current density (JC) was porous YCaBa2Cu3Oy which was 2.32 A/cm2 compared to 0.75 A/cm2 for porous YCaBa4Cu6Oy at 60 K. The critical temperature for porous structure was less than non porous structure for Ca doped Y146 system which was 69.9 K and 67.9 K. SEM micrograph unveiled that the Jc was induced significantly by continuity of grain formation via grain size. Pores homogenized the grains surface quality and connectivity due to strain release thus increasing effective cross section of the sample for current density (Jc) over the vast areas.


1999 ◽  
Vol 325 (3-4) ◽  
pp. 109-117 ◽  
Author(s):  
J.Q Li ◽  
C.C Lam ◽  
J.S Abell ◽  
G.B Peacock ◽  
P.P Edwards ◽  
...  

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Kazumasa Iida ◽  
Dongyi Qin ◽  
Chiara Tarantini ◽  
Takafumi Hatano ◽  
Chao Wang ◽  
...  

AbstractThe most effective way to enhance the dissipation-free supercurrent in the presence of a magnetic field for type II superconductors is to introduce defects that act as artificial pinning centers (APCs) for vortices. For instance, the in-field critical current density of doped BaFe2As2 (Ba122), one of the most technologically important Fe-based superconductors, has been improved over the last decade by APCs created by ion irradiation. The technique of ion irradiation has been commonly implemented to determine the ultimate superconducting properties. However, this method is rather complicated and expensive. Here, we report a surprisingly high critical current density and strong pinning efficiency close to the crystallographic c-axis for a K-doped Ba122 epitaxial thin film without APCs, achieving performance comparable to ion-irradiated K-doped Ba122 single crystals. Microstructural analysis reveals that the film is composed of columnar grains with widths of approximately 30–60 nm. The grains are rotated around the b- (or a-) axis by 1.5° and around the c-axis by −1°, resulting in the formation of low-angle grain boundary networks. This study demonstrates that the upper limit of in-field properties reached in ion-irradiated K-doped Ba122 is achievable by grain boundary engineering, which is a simple and industrially scalable manner.


1991 ◽  
Vol 235 ◽  
Author(s):  
Sang Yeol Lee ◽  
Eiki Narumi ◽  
David T. Shaw

ABSTRACTMultilayers of Y1Ba2Cu3O7-y/Y1Ba2(Cu1−xNix)3O7-ysuperconducting thin films have been grown epitaxially on (100) ZrO2 substrates using a pulsed laser deposition technique. The thickness of the Y1Ba2Cu3O7-y layer was varied from 60 Å to 900 Å and the thickness of the Y1Ba2(Cu1−xNix3O7-y layer was varied from 60 A to 100 A to determine the effect of the Ni-doped layers on the superconducting properties. Variations of critical current density were investigated as a function of temperature in magnetic fields up to 5 T. Magnetic field dependence of normalized critical current density, Jc(H)/Jc(O), is improved by the growth of Ni-doped multilayer structures, possibly due to an increase in flux pinning force.


Crystals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Anota Ijaduola ◽  
Rai Shipra ◽  
Athena Sefat

This study investigated the application of pressure on the superconducting properties of a thallium-based cuprate, namely Tl2Ba2Ca2Cu3O9-δ (Tl-2223). The superconducting transition temperature (Tc) and the critical current density (Jc) were studied by applying ~1 GPa of pressure. This hydrostatic pressure was applied in a piston-cylinder-cell (PCC), using Pb as a manometer and Daphne 7373 oil as the pressure transmitting medium. For estimating the Jc, we used Bean’s critical state formula on the magnetic hysteresis curves at 10 K and 20 K. Both the Tc and Jc improved with pressure. The Jc values increased at both temperatures and the Tc value increased by 4 K with a pressure of 0.8 GPa. These results clearly indicate that pressure is another tool to control properties of quantum materials.


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