scholarly journals Study of Y1Ba2Cu3O7−δ+CuO Nanocomposite as a Resistive Current Limiter

2019 ◽  
Vol 19 (02) ◽  
pp. 1950010 ◽  
Author(s):  
A. V. Ushakov ◽  
I. V. Karpov ◽  
V. G. Demin ◽  
A. A. Shaihadinov ◽  
A. I. Demchenko ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
High Speed ◽  
High Efficiency ◽  
High Temperature Superconductors ◽  
Experimental Studies ◽  
Cuo Nanoparticles ◽  
Current Switch ◽  
Current Limiter

The influence of CuO nanoscale inclusions as the second component of the composites on the transport properties of superconducting polycrystals YBa2Cu3O7 was studied. Samples of YBa2Cu3O[Formula: see text] with different content of CuO nanoparticles were synthesized. The analysis of magnetic properties was carried out within the framework of the extended critical state model. It was found that the addition of 20[Formula: see text]wt.% CuO nanoparticles leads to an increase in the critical current density at [Formula: see text][Formula: see text]K. A further increase to 30[Formula: see text]wt.% reduces the critical current density. The results of the experimental studies of a switching superconducting fault current limiter in AC voltage networks based on high-temperature superconductors (HTSC) of the 2nd generation are given in this work. The testing equipment contains a series-connected HTSC module and a high-speed current switch with a break time of 9[Formula: see text]ms. The high efficiency of the samples made from the YBa2Cu3O[Formula: see text] + CuO nanocomposite material as an active element of a resistive current limiter is shown.

Effect of ZnO Nano-Oxide Addition on the Superconducting Properties of the (Bi.Pb)2223 Phase

2011 ◽  
Vol 324 ◽  
pp. 241-244 ◽  
Author(s):  
R. Mawassi ◽  
R. Awad ◽  
Mohamad Roumie ◽  
M. Kork ◽  
I. Hassan
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
High Temperature Superconductors ◽  
Weak Links ◽  
Superconducting Properties ◽  
X Ray ◽  
Weight Percentage ◽  
Nano Oxide

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).

Crystal Growth of High Temperature Superconductors

MRS Bulletin ◽  
1988 ◽  
Vol 13 (10) ◽  
pp. 56-61 ◽  
Author(s):  
H.J. Scheel ◽  
F. Licci
Keyword(s):  
High Temperature ◽  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Large Scale ◽  
High Temperature Superconductivity ◽  
High Temperature Superconductors ◽  
Superconducting Transition ◽  
Theoretical Understanding

The discovery of high temperature superconductivity (HTSC) in oxide compounds has confronted materials scientists with many challenging problems. These include the preparation of ceramic samples with critical current density of about 106 A/cm2 at 77 K and sufficient mechanical strength for large-scale electrotechnical and magnetic applications and the preparation of epitaxial thin films of high structural perfection for electronic devices.The main interest in the growth of single crystals is for the study of physical phenomena, which will help achieve a theoretical understanding of HTSC. Theorists still do not agree on the fundamental mechanisms of HTSC, and there is a need for good data on relatively defect-free materials in order to test the many models. In addition, the study of the role of defects like twins, grain boundaries, and dislocations in single crystals is important for understanding such parameters as the critical current density. The study of HTSC with single crystals is also expected to be helpful for finding optimum materials for the various applications and hopefully achieving higher values of the superconducting transition temperature Tc than the current maximum of about 125 K. It seems unlikely at present that single crystals will be used in commercial devices, but this possibility cannot be ruled out as crystal size and quality improve.

Study on the High Speed Jet-Electrode Position Ni-P Alloy

2013 ◽  
Vol 567 ◽  
pp. 39-44
Author(s):  
Ying Wang ◽  
Min Kang ◽  
Yong Yang ◽  
Xiu Qing Fu
Keyword(s):  
Grain Size ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
High Speed ◽  
Electrode Position ◽  
Stirring Intensity

The high speed jet-electrodepositing equipment was used to prepare Ni-P alloy in substrate of 45 steel. The influences of current density on depositing rate, hardness of deposit and microstructure of Ni-P alloy were studied, and the comparation with that of conventional electroplating were studied. The results show that with the increase of stirring intensity of the electrolyte, the thickness of diffused layer decreases, the critical current density increases, and then the depositing rates increase to 69.82/min. A linear increasing of the depositing rate with the increase of current density is observed, and it refines grain size obviously. Deposit hardness up to 679HV.

TEM Characterization of Grain Boundary Structure in YBCO Coated Conductors

2000 ◽  
Vol 6 (S2) ◽  
pp. 394-395
Author(s):  
H. Kung ◽  
J.P. Hirth ◽  
S.R. Foltyn ◽  
P.N. Arendt ◽  
Q.X. Jia ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Grain Boundaries ◽  
Critical Current ◽  
Current Density ◽  
Lattice Mismatch ◽  
Coupling Effect ◽  
High Temperature Superconductors ◽  
Coated Conductors ◽  
Boundary Structure

Studies of defects, such as grain boundaries, in high temperature superconductors (HTS) are important due to the interaction of the defects with flux-bearing vortices. The benefit of in-plane grain alignment has been documented in YBCO thin film bicrystals, in which the high critical current density (Jc) observed across small angle grain boundaries deteriorates exponentially with grain boundary angles beyond ∼ 7°. In addition to the weak coupling effect, a grain boundary may also influence the transport properties via the grain boundary dislocations (GBDs) serving as pinning centers to increase the critical current density. There have been a number of studies on grain boundary structures in YBCO. Despite many differences in structure among the different types of boundaries, it has been established that the low angle [001] tilt boundary in YBCO consists of aperiodic array of edge type GBDs with [100] type Burgers vector that accommodate the lattice mismatch, and the regions between the GBDs are channels of relatively undisturbed lattices [1].

INFLUENCE OF CRITICAL CURRENT DENSITY ON MAGNETIC FORCE OF HTSC BULK ABOVE PMR WITH 3D-MODELING NUMERICAL SOLUTIONS

2011 ◽  
Vol 25 (19) ◽  
pp. 2525-2532 ◽  
Author(s):  
YIYUN LU ◽  
BINGJUAN LU ◽  
YUNWANG GE ◽  
WENQING CHEN
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
3D Modeling ◽  
Magnetic Force ◽  
Numerical Solutions ◽  
Magnetic Levitation ◽  
High Temperature Superconductors ◽  
Levitation System ◽  
Superconducting Levitation

Numerical electromagnetic field simulations of high-temperature superconductors (HTSC) bulk were carried out to calculate the magnetic force between the HTSC bulk and the permanent magnet railway (PMR). A 3D-modeling numerical calculation method is proposed using the finite element method. The model is formulated with the magnetic field vector (H-method). The resulting code was written with FORTRAN language. The electric field intensity E and the current density J constitutive relation of HTSC were described with E–J power law. The Kim macro-model is used to describe critical current density Jc of HTSC bulk. Two virtual HTSC bulks were used to solve the critical current density Jc anisotropic properties of HTSC materials. A superconducting levitation system composed of one HTSC bulk and PMR is successfully investigated using the proposed method. By this method, the influence of critical current density on magnetic levitation force of the superconducting levitation system is mathematically studied.

scholarly journals Enhancement of Critical Current Density of Yttrium Barium Copper Oxide Thin Films by Introducing Nano dimensional Cerium Oxide Defects

2018 ◽  
Vol 10 (6) ◽  
pp. 109
Author(s):  
Tochukwu Emeakaroha ◽  
Floyd James ◽  
Abebe Kebede
Keyword(s):  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
High Temperature Superconductors ◽  
Flux Line ◽  
Buffer Layers ◽  
Line Lattice ◽  
Ceo2 Films ◽  
Magnetic Flux Line

The critical current density, Jc  has been the most important parameter used in the design and engineering of effective devices which is one of the implementation of high temperature superconductors (HTSC). In this work, an effort has been made to further improve the critical current density of YBa2Cu3O7-x (YBCO) thin films by preventing the magnetic flux line lattice against the Lorentz force by pinning it in place with the aid of nano-dimensional defects. These defects were generated by distributing nano sized CeO2 islands after YBCO layer was created on LaAlO3 substrates perpendicular to the film using pulsed laser deposition (PLD) technique. Three samples with buffer layers of CeO2 were prepared. CeO2 with 50 pulses, 100 pulses and 150 pulses, after each 1000 pulses of YBCO were prepared five layers for each of the samples. The structural characterization of YBCO/CeO2 and YBCO pristine films were carried out using x-ray diffraction (XRD) and scanning electron microscopy (SEM). Superconducting proprieties were measured using a vibrating sample magnetometer (VSM). Jc  for the pure YBCO and the YBCO/CeO2 films were calculated from magnetization (M) versus Field (H) loops using Bean’s model. Jc  for the 50 pulses of YBCO/CeO2 films was found to be increased slightly by an order of magnitude of about 40% with respect to those of YBCO films without the nano dimensional defects.

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