MAGNETIC HYSTERESIS OF HIGH-TEMPERATURE YBa2Cu3Ox-AgO SUPERCONDUCTORS: EXPLANATION OF MAGNETIC SUSPENSION

1988 ◽  
Vol 02 (07) ◽  
pp. 869-874 ◽  
Author(s):  
C.Y. HUANG ◽  
Y. SHAPIRA ◽  
E.J. MCNIFF ◽  
P.N. PETERS ◽  
B.B. SCHWARTZ ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Simple Model ◽  
Hysteresis Loop ◽  
Applied Magnetic Field ◽  
Magnetic Hysteresis ◽  
Magnetic Suspension ◽  
Pinning Centers ◽  
Strong Pinning

We have measured the magnetization M of superconducting YBa 2 Cu 3 O x- AgO composites with T c approximately equal to 92K as a function of an applied magnetic field H at 77 and 87K. A very pronounced M-H hysteresis loop occurs even at 87K, indicating the presence of extremely strong pinning centers. The results of these measurements, together with a simple model, explain quantitatively why these superconductors could be suspended below a magnet.

Weak Pinning Centers in Proton Irradiated YBCO Single Crystals

1991 ◽  
Vol 235 ◽  
Author(s):  
Y. J. Zhao ◽  
J. R. Liu ◽  
Y. K. Tao ◽  
P. H. Hor ◽  
W. K. Chu
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Normal State ◽  
Flux Line ◽  
Pinning Centers ◽  
Weak Center ◽  
Radiation Induced ◽  
Strong Pinning ◽  
Weak Pinning ◽  
Ybco Single Crystal

ABSTRACTObserved magnetic Jc enhancement in a 3.4 MeV proton-irradiated Y1Ba2Cu3O7-δ (YBCO) single crystal are shown to be intimately linked with a kind of weak pinning centers. Applied magnetic field transforms weak centers into the normal state or pinning centers, which then cause pinning enhancement. Strong pinning anisotropy of the radiation induced weak center can be explained very well by the size anisotropy of a superconducting unit cell and a flux line, or the coherence length.

FEM-simulation of superconducting linear acceleration system for pellet injection

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1469-1475
Author(s):  
Teruou Takayama ◽  
Takazumi Yamaguchi ◽  
Ayumu Saitoh ◽  
Atsushi Kamitani
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Applied Magnetic Field ◽  
Integration Method ◽  
Fem Simulation ◽  
Linear Acceleration ◽  
Regularization Technique ◽  
Acceleration Time ◽  
Pellet Injection ◽  
Improper Integrals

In order to simulate the high-temperature superconducting (HTS) linear acceleration (SLA) system for the pellet injection, the integration method of the applied magnetic field generated from the acceleration coil has been proposed. To this end, the regularization technique is used in the evaluation of the improper integrals, and simultaneously, a FEM code is developed for analyzing the shielding current density in an HTS film. In addition, the SLA system has been simulated using the code. The results of the computations show that the accuracy of the applied magnetic field is considerably improved. In this sense, the regularization technique is a useful tool. Also by locating the outer coil, the acceleration time during which the pellet speed reaches 5 km/s is about 3.5 times shorter than that of the only use of the inner coil. These results mean that the outer coil is effective in the improvement of the acceleration performance for the SLA system.

scholarly journals Harmonic analysis and modelling of magnetisation process in soft ferromagnetic material

2017 ◽  
Vol 30 (1) ◽  
pp. 121-136
Author(s):  
Branko Koprivica ◽  
Ioan Dumitru ◽  
Alenka Milovanovic ◽  
Ovidiu Caltun
Keyword(s):  
Magnetic Field ◽  
Hysteresis Loop ◽  
Magnetic Induction ◽  
Domain Walls ◽  
Magnetic Hysteresis ◽  
Magnetic Domain ◽  
Fast Fourier Transformation ◽  
Induced Voltage ◽  
Harmonic Content ◽  
Excitation Magnetic Field

The aim of this paper is to present a research of magnetic hysteresis loops of a toroidal ferromagnetic core made of electrical steel. The experimental results of induced voltage, magnetic induction and hysteresis loop obtained at different frequencies of the sinusoidal excitation magnetic field have been presented. The harmonic content of the induced voltage and magnetic induction have been calculated using Fast Fourier Transformation. Observed variation of higher harmonics with frequency has been correlated to the mechanism of magnetic domain walls damping. A variation of harmonics of the magnetic induction with the amplitude of the excitation magnetic field has been analysed and a proper mathematical model has been proposed. Furthermore, the influence of the triangularly shaped excitation magnetic field and the distorted shape excitation that produces sinusoidal induction on the shape of hysteresis loop and harmonic content of the induced voltage and the magnetic induction has been analysed and discussed.

Hysteresis Loop Shifts in Magnetic Field Cooled FeOOH Nanoparticles

1999 ◽  
Vol 581 ◽  
Author(s):  
M.S. Seehra ◽  
Paromita Roy ◽  
A. Manivannan
Keyword(s):  
Magnetic Field ◽  
Hysteresis Loop ◽  
Spin Glass ◽  
Applied Magnetic Field ◽  
Magnetic Moment ◽  
Open Loop ◽  
Zero Field ◽  
Interparticle Interactions

ABSTRACTMeasurements of the magnetization M as a function of temperature (5K - 300K) and applied magnetic field H (up to 50 kOe) in 30 Å particles of FeOOH are reported. M increases with decreasing T, peaking at TB = 65 K below which the ZFC (zero-field-cooled) and the FC (field-cooled) data separate. Hysteresis loop measured at 10 K for ZFC shows an open loop up to 40 kOe with coercivity = 2 kOe. For the FC case, the loop shifts and the loop-shift increases with the cooling field ItL, approaching saturation above Hc = 20 kOe. From the variation of M vs H above TB, a magnetic moment/particle μp = 300 μB is determined. These results suggest that the FeOOH nanoparticles have an antiferromagnetically ordered core with uncompensated surface spins yielding μp and the surface spins order in a spin-glass-like state below TB, possibly due to interparticle interactions.

scholarly journals Механизм формирования критического тока высокотемпературных сверхпроводников, содержащих сквозные микроскопические дефекты

2021 ◽  
Vol 63 (1) ◽  
pp. 65
Author(s):  
А.Н. Максимова ◽  
В.А. Кашурников ◽  
А.Н. Мороз ◽  
И.А. Руднев
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Magnetic Flux ◽  
Critical Current ◽  
High Temperature Superconductor ◽  
Physical Mechanism ◽  
Characteristic Size ◽  
Pinning Centers ◽  
The Magnetic Field ◽  
Qualitative Picture

The critical current of a model high-temperature superconductor (HTSC) with defects in the form of through holes (antidots) with a characteristic size greater than or of the order of the penetration depth of the magnetic field is calculated. To do this, the subprocesses equivalent to the trapping of the magnetic flux by the hole and the creation of a vortex at the edge of the hole are introduced into the model of layered HTSC. It is shown that accounting for these subprocesses leads to the appearance of a physical mechanism that allows us to correctly describe the non-monotonic dependence of the critical current on the characteristic size of the antidot, similar to that observed in the experiment. Calculations were performed for a pure superconductor and a superconductor containing nanoscale pinning centers. It is shown that the presence of nanoscale pinning centers along with antipoints does not change the qualitative picture of the influence of the antidot radius on the pinning character of the magnetic flux and the behavior of the critical current in the HTSC.

Implications of magnetic-hysteresis-loop scaling in high-temperature superconductors

1995 ◽  
Vol 51 (13) ◽  
pp. 8513-8520 ◽  
Author(s):  
G. K. Perkins ◽  
L. F. Cohen ◽  
A. A. Zhukov ◽  
A. D. Caplin
Keyword(s):  
High Temperature ◽  
Hysteresis Loop ◽  
High Temperature Superconductors ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop

scholarly journals Antiferromagnetic order induced by an applied magnetic field in a high-temperature superconductor

Nature ◽  
2002 ◽  
Vol 415 (6869) ◽  
pp. 299-302 ◽  
Author(s):  
B. Lake ◽  
H. M. Rønnow ◽  
N. B. Christensen ◽  
G. Aeppli ◽  
K. Lefmann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Applied Magnetic Field ◽  
High Temperature Superconductor ◽  
Antiferromagnetic Order

scholarly journals High-Temperature Anyon Superconductivity

1997 ◽  
Vol 11 (01) ◽  
pp. 1-8 ◽  
Author(s):  
E. J. Ferrer ◽  
R. Hurka ◽  
V. De La Incera
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Boundary Conditions ◽  
Applied Magnetic Field ◽  
Short Range ◽  
Superconducting Materials ◽  
Finite Density ◽  
High Temperature Superconducting

The screening of an applied magnetic field in a charged anyon fluid at finite density (μ≠0) and temperature (T≠0) is investigated. Using the semi-infinite sample boundary conditions we find, at densities typical of high-temperature superconducting materials, that the anyon fluid exhibits a superconducting behavior. The total Meissner screening is characterized by two penetration lengths, corresponding to two short-range eigenmodes of propagation within the anyon fluid.

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