A.c. magnetic field induced microwave absorption in high temperature superconductor Tl2Ba2Ca2Cu3Ox

1994 ◽  
Vol 91 (11) ◽  
pp. 919-922
Author(s):  
F.J. Owens
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Microwave Absorption ◽  
High Temperature Superconductor

The activation energy U(T,B) in high temperature superconductor

2020 ◽  
Vol 92 (2) ◽  
pp. 20601
Author(s):  
Abdelaziz Labrag ◽  
Mustapha Bghour ◽  
Ahmed Abou El Hassan ◽  
Habiba El Hamidi ◽  
Ahmed Taoufik ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Activation Energy ◽  
Phase Diagram ◽  
High Temperature ◽  
Apparent Activation Energy ◽  
High Temperature Superconductor ◽  
Flux Flow ◽  
Resistivity Measurements ◽  
Vortex Phase ◽  
The Magnetic Field

It is reported in this paper on the thermally assisted flux flow in epitaxial YBa2Cu3O7-δ deposited by Laser ablation method on the SrTiO3 substrate. The resistivity measurements ρ (T, B) of the sample under various values of the magnetic field up to 14T in directions B∥ab-plane and B∥c-axis with a dc weak transport current density were investigated in order to determine the activation energy and then understand the vortex dynamic phenomena and therefore deduce the vortex phase diagram of this material. The apparent activation energy U0 (B) calculated using an Arrhenius relation. The measured results of the resistivity were then adjusted to the modified thermally assisted flux flow model in order to account for the temperature-field dependence of the activation energy U (T, B). The obtained values from the thermally assisted activation energy, exhibit a behavior similar to the one showed with the Arrhenius model, albeit larger than the apparent activation energy with ∼1.5 order on magnitude for both cases of the magnetic field directions. The vortex glass model was also used to obtain the vortex-glass transition temperature from the linear fitting of [d ln ρ/dT ] −1 plots. In the course of this work thanks to the resistivity measurements the upper critical magnetic field Hc2 (T), the irreversibility line Hirr (T) and the crossover field HCrossOver (T) were located. These three parameters allowed us to establish a phase diagram of the studied material where limits of each vortex phase are sketched in order to optimize its applicability as a practical high temperature superconductor used for diverse purposes.

scholarly journals Measurements and Analysis of AC Losses in HTS Windings of Electrical Machine for Different Operation Modes

2021 ◽  
Vol 11 (6) ◽  
pp. 2741
Author(s):  
Sergey Zanegin ◽  
Nikolay Ivanov ◽  
Vasily Zubko ◽  
Konstantin Kovalev ◽  
Ivan Shishov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
High Temperature Superconductors ◽  
Transport Current ◽  
Operating Conditions ◽  
Ac Losses ◽  
Electrical Machine ◽  
2Nd Generation ◽  
Motor Mode

The article is devoted to the study of losses in devices based on high-temperature superconductors of the 2nd generation. The complexity of the devices under study increases from a single rack coil to a winding assembled from several coils, and finally to an electric machine operating in generator mode. This is the way to experimentally study the behavior of 2nd generation high temperature superconductor (2G HTS) carrying a transport current in various conditions: self-field, external DC, and AC magnetic field. Attention is also paid to the losses in the winding during its operation from the inverter, which simulates the operating conditions in the motor mode of a propulsion system.

Magnetic Coupling in La0.7Ca0.3MnO3/YBa2Cu3O7/La0.7Ca0.3MnO3 Trilayers

2009 ◽  
Vol 289-292 ◽  
pp. 303-309
Author(s):  
N.M. Nemes ◽  
C. Visani ◽  
J. Garcia-Barriocanal ◽  
F.Y. Bruno ◽  
Z. Sefrioui ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Carrier Density ◽  
High Temperature Superconductor ◽  
Hysteresis Loops ◽  
Magnetic Coupling ◽  
Oxygen Depletion ◽  
Free Carrier ◽  
Half Metallic ◽  
Free Carrier Density

We report on the interplay between ferromagnetism and superconductivity in trilayers La0.7Ca0.3MnO3/YBa2Cu3O7/La0.7Ca0.3MnO3 made of half metallic manganite and high temperature superconductor cuprate. Samples with a fully oxygenated cuprate show a magnetic field interval where the magnetizations of the manganite are aligned antiparallel. A considerable magnetoresistance accompanies the switching between magnetization configurations (parallel vs. antiparallel) of the manganite moments. Suppression of the free carrier density of the cuprate which occurs upon oxygen depletion, results in deep modifications in the shape of the normal state hysteresis loops indicating that there may be a magnetic coupling mediated by free carrier density of the cuprate. This result outlines the importance of quasiparticle transmission in the interplay between ferromagnetism and superconductivity in this kind of samples.

HIGH MAGNETIC FIELD HALL EFFECT AND MAGNETORESISTANCE STUDIES OF Y-Ba-Cu-O: A HIGH Tc SUPERCONDUCTOR

1987 ◽  
Vol 01 (02) ◽  
pp. 413-417
Author(s):  
J.D. Hettinger ◽  
A.G. Swanson ◽  
J.S. Brooks ◽  
Y.P. Ma
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Transition Temperature ◽  
Hall Effect ◽  
High Temperature Superconductor ◽  
Strong Dependence ◽  
Zero Magnetic Field ◽  
High Tc ◽  
Relative Percentage ◽  
High Tc Superconductor

We have measured the transition temperature, critical field, magnetoresistance, and Hall effect for the high temperature superconductor Y-Ba-Cu-O in magnetic fields up to 23T in the temperature range 4.2 to 125K. Meissner studies at zero magnetic field were also performed in some cases. We find a strong dependence of these parameters on the relative percentage of the correct phase of Y-Ba-Cu-O in the sample. We report new results on magnetoresistance and Hall effect in these materials.

Process of magnetic field penetration into the high-temperature superconductor YBa2Cu3O7−δ

2000 ◽  
Vol 42 (8) ◽  
pp. 1398-1402 ◽  
Author(s):  
V. M. Arzhavitin ◽  
N. N. Efimova ◽  
M. B. Ustimenkova ◽  
V. A. Finkel’
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
Magnetic Field Penetration ◽  
Field Penetration

Magnetic field penetration into the high temperature superconductor YBa2Cu3O7−x

1989 ◽  
Vol 156-157 ◽  
pp. 867-870 ◽  
Author(s):  
A. Mansour ◽  
R.O. Hilleke ◽  
G.P. Felcher ◽  
R.B. Laibowitz ◽  
P. Chaudhari ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
Magnetic Field Penetration ◽  
Field Penetration

scholarly journals Comparison of Pr-doped Ca 122 and Ca 112 Pnictides by Low-field Microwave Absorption Spectroscopy

2014 ◽  
Vol 1684 ◽  
Author(s):  
Austin R. Howard ◽  
Jonathan D. Yuen ◽  
Bing Lv ◽  
Myron Salamon ◽  
Ching-Wu Chu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Microwave Absorption ◽  
Absorption Spectroscopy ◽  
Superconducting State ◽  
Superconducting Phase ◽  
Interfacial Phase ◽  
Low Field ◽  
Low Magnetic Field ◽  
Anisotropic Magnetization

ABSTRACTPraseodymium doped CaFe2As2 (122 structure) and CaFeAs2 (112 structure) are characterized by modulated Low Magnetic Field Microwave Absorption (LFMA) spectroscopy. In both (Pr,Ca)122 and (Pr,Ca)112 structures, a strong hysteretic LFMA is found, with a TcH of ∼30 K and ∼26 K, respectively. However, in (Pr,Ca)122, measurements also show an unusual Narrow Peak (NP) LFMA signal appearing at higher temperatures, above the lower TcH superconducting state until a TcNP of 49 K. We associate this NP LFMA with interfacial superconductivity, which has been found previously by highly anisotropic magnetization measurements. Furthermore, the absence of NP in (Pr,Ca)112 correlates with the absence of an interfacial phase. These results give useful information about the microwave signature of interfacial superconductivity present in the (Pr,Ca)122 system, and may form a roadmap towards a stabilized high temperature superconducting phase in pnictides.

scholarly journals Magnetic-field-induced charge-stripe order in the high-temperature superconductor YBa2Cu3Oy

Nature ◽  
2011 ◽  
Vol 477 (7363) ◽  
pp. 191-194 ◽  
Author(s):  
Tao Wu ◽  
Hadrien Mayaffre ◽  
Steffen Krämer ◽  
Mladen Horvatić ◽  
Claude Berthier ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
Stripe Order ◽  
Charge Stripe ◽  
Induced Charge
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