Enhancement of superconducting critical current density by Fe impurity substitution in NbSe2 single crystals and the vortex pinning mechanism

2017 ◽  
Vol 19 (18) ◽  
pp. 11230-11238 ◽  
Author(s):  
Rukshana Pervin ◽  
Manikanadan Krishnan ◽  
Amit Kumar Rana ◽  
M. Kannan ◽  
S. Arumugam ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Vortex Pinning ◽  
Pinning Mechanism ◽  
Fe Impurity

This study demonstrates the temperature dependence of Hsb and Hlb for (a) NbSe2, (b) Fe0.0008NbSe2 and (c) Fe0.0011NbSe2 fitted with the δl and δTc pinning mechanism, respectively.

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.

Field and temperature dependence of critical current density of Fe doped Bi2212 single crystals

2000 ◽  
Vol 341-348 ◽  
pp. 1351-1352 ◽  
Author(s):  
K.K. Uprety ◽  
J. Horvat ◽  
X.L. Wang ◽  
G.D. Gu ◽  
H.K. Liu ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density

scholarly journals Giant increase of critical current density and vortex pinning in Mn doped KxFe2−ySe2 single crystals

2014 ◽  
Vol 105 (19) ◽  
pp. 192602 ◽  
Author(s):  
Mingtao Li ◽  
La Chen ◽  
Wen-Long You ◽  
Junyi Ge ◽  
Jincang Zhang
Keyword(s):  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Vortex Pinning ◽  
Mn Doped

scholarly journals Critical Current Density and Vortex Dynamics in Pristine and Irradiated KCa2Fe4As4F2

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5283
Author(s):  
Sunseng Pyon ◽  
Soichi Taya ◽  
Yuto Kobayashi ◽  
Ayumu Takahashi ◽  
Wenjie Li ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Vortex Dynamics ◽  
Dose Dependence ◽  
Vortex Pinning ◽  
Particle Irradiation ◽  
Before And After ◽  
Large Anisotropy

We report the critical current density (Jc) and vortex pinning properties in single crystals of a novel iron-based superconductor (IBS) KCa2Fe4As4F2 with large Jc in the pristine state, before and after introduction of artificial defects by swift-particle irradiation. The effects of 2.6 GeV U and 3 MeV proton irradiations in KCa2Fe4As4F2 single crystals on transition temperature Tc and Jc, including its dose dependence, are systematically studied. Jc~8 MA/cm2 under a self-field at 2 K in the pristine crystal is strongly enhanced up to 19.4 and 17.5 MA/cm2 by irradiation of 2.6 GeV U-ions and 3 MeV protons, respectively. Suppression of Tc and dose dependence of Jc in KCa2Fe4As4F2 is different from that in a representative IBS of (Ba,K)Fe2As2, which can be explained by considering the presence of embedded defects in pristine KCa2Fe4As4F2. The vortex dynamics in the pristine and proton irradiated KCa2Fe4As4F2 single crystals are also investigated from the analyses of the field dependence of Jc and the normalized magnetic relaxation rate. In addition to the contribution of embedded defects, weak collective pinning is considered for comprehensive analyses. Vortex dynamics in KCa2Fe4As4F2 is similar to those in (Ba,K)Fe2As2 to some extent, and different from that in anisotropic Li0.8Fe0.2OHFeSe. Large anisotropy, due to the presence of insulating blocking layers in KCa2Fe4As4F2, which leads to much lower irreversibility field (Hirr) compared with 122-type IBSs, strongly affect the vortex dynamics.

Temperature dependence of the intragrain critical current density in polycrystalline Ag-sheathed Bi(2223) tapes

1999 ◽  
Vol 9 (2) ◽  
pp. 2659-2662 ◽  
Author(s):  
G. Grasso ◽  
M.R. Cimberle ◽  
C. Ferdeghini ◽  
A.S. Siri ◽  
F. Marti ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Temperature Dependence ◽  
Critical Current ◽  
Current Density

scholarly journals Influence of the carbon substitution on the critical current density and AC losses in MgB2 single crystals

2010 ◽  
Vol 78 (3) ◽  
pp. 359-365 ◽  
Author(s):  
M. Ciszek ◽  
K. Rogacki ◽  
K. Oganisian ◽  
N. D. Zhigadlo ◽  
J. Karpinski
Keyword(s):  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Ac Losses ◽  
Carbon Substitution
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