Low‐field flux pinning in twinned and detwinned single crystals of YBa2Cu3O7−x

1991 ◽  
Vol 58 (14) ◽  
pp. 1566-1568 ◽  
Author(s):  
L. J. Swartzendruber ◽  
D. L. Kaiser ◽  
F. W. Gayle ◽  
L. H. Bennett ◽  
A. Roytburd
Keyword(s):  
Single Crystals ◽  
Flux Pinning ◽  
Low Field

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Suppression of Ferromagnetism in EuxCa1-xB6

2012 ◽  
Vol 190 ◽  
pp. 97-100 ◽  
Author(s):  
V.V. Glushkov ◽  
A.V. Kuznetsov ◽  
I. Sannikov ◽  
A.V. Bogach ◽  
S.V. Demishev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Curie Temperature ◽  
Single Crystals ◽  
Effective Magnetic Moment ◽  
Paramagnetic State ◽  
Low Field ◽  
Wide Range ◽  
Free Ion ◽  
The Eu

We report the magnetic properties of EuxCa1-xB6 single crystals (0.756x1) studied in the wide range of temperatures (1.8-300 K) and magnetic fields (up to 50 kOe). It was found that low field magnetic susceptibility χ (T) follows the Curie-Weiss law χ~(T-Θp)-1 at high temperatures for all the concentrations studied. The effective magnetic moment of the Eu2+ ion estimated from the data diminishes from the free ion value μeff7.93μB (μB - Bohr magneton) for x=1 to μeff7.3μB for x=0.756. A universal behavior of magnetic susceptibility χ~(T-Θ)-α (α=1.5) is detected close to the Curie temperature TC in the paramagnetic state at both metallic (x>xC~0.8) and dielectric (xC.

Enhanced flux pinning and fishtail effect in spiral grown Bi2Sr2CaCu2Oy single crystals

1997 ◽  
Vol 282-287 ◽  
pp. 2125-2126 ◽  
Author(s):  
X.L. Wang ◽  
J. Horvat ◽  
H.K. Liu ◽  
S.X. Dou
Keyword(s):  
Single Crystals ◽  
Flux Pinning

Flux Pinning in Y1Ba2Cu3O7-∂ Single Crystals

1988 ◽  
pp. 267-271 ◽  
Author(s):  
L. Fruchter ◽  
C. Giovannella ◽  
G. Collin ◽  
I. A. Campbell
Keyword(s):  
Single Crystals ◽  
Flux Pinning

Low field flux dynamics of Pr-doped Bi-2212 single crystals

2000 ◽  
Vol 341-348 ◽  
pp. 1159-1160
Author(s):  
Y.Y. Hsu ◽  
Y. Huang ◽  
H.C. Ku
Keyword(s):  
Single Crystals ◽  
Flux Dynamics ◽  
Low Field

Anisotropic critical current density and flux pinning mechanism of Fe1+yTe0.6Se0.4 single crystals

2021 ◽  
Author(s):  
Yongqiang Pan ◽  
Nan Zhou ◽  
Bencheng Lin ◽  
Jinhua Wang ◽  
Zengwei Zhu ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Flux Pinning ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Pinning Force ◽  
Magnetization Relaxation ◽  
Pinning Mechanism

Abstract Fe1+yTe0.6Se0.4 has considerable application potential due to its large critical current density (J c) and high upper critical magnetic field (H c2). However, the uncertainty of the anisotropy of J c and the unclear flux-pinning mechanism have limited the application of this material. In this study, the J c in three directions were obtained from magnetic hysteresis loop measurements. A large anisotropy of J c ab /J c c ~ 10 was observed, and the origin of the anisotropy was discussed in details. Flux pinning force densities (F p) were obtained from J c, and a non-scaling behavior was found in the normalized pinning force f p[F p/F p-max] versus the normalized field h[H/H c2]. The peaks of pinning force shift from a high h to a low h with increasing temperature. Based on the vortex dynamics analysis, the peak shift was found to originate from the magnetization relaxation. The J c and F p at critical states free from the magnetic relaxation were regained. According to the Dew-Hughes model, the dominant pinning type in Fe1+yTe0.6Se0.4 clean single crystals was confirmed to be normal point pinning.

Effect of Heavy Ion Irradiation on Flux Pinning Properties of Bi2212 and Bi(Pb)2212 Single Crystals Having Various γ 2

1999 ◽  
pp. 465-468 ◽  
Author(s):  
Jun-ichi Shimoyama ◽  
Yuri Nakayama ◽  
Teruki Motohashi ◽  
Kenji Otzschi ◽  
Noriko Chikumoto ◽  
...  
Keyword(s):  
Single Crystals ◽  
Flux Pinning ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Heavy Ion Irradiation ◽  
Pinning Properties

Dramatically Improved Flux Pinning Properties of Heavily Pb-Doped Bi2212 Single Crystals and Ag Composite Tapes

1998 ◽  
pp. 279-284 ◽  
Author(s):  
J. Shimoyama ◽  
Y. Nakamama ◽  
T. Motohashi ◽  
T. Fujita ◽  
T. Yamada ◽  
...  
Keyword(s):  
Single Crystals ◽  
Flux Pinning ◽  
Pinning Properties

Comparison of flux pinning enhancement in fast neutron irradiated Bi-2212 single crystals and polycrystalline melt samples

1991 ◽  
Vol 185-189 ◽  
pp. 2273-2274 ◽  
Author(s):  
W. Gerhäuser ◽  
H.-W. Neumüller ◽  
W. Schmidt ◽  
G. Ries ◽  
G. Saemann-Ischenko ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Single Crystals ◽  
Flux Pinning
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