scholarly journals Magnetization relaxation, critical current density, and vortex dynamics in aBa0.66K0.32BiO3+δsingle crystal

2015 ◽  
Vol 91 (21) ◽  
Author(s):  
Jian Tao ◽  
Qiang Deng ◽  
Huan Yang ◽  
Zhihe Wang ◽  
Xiyu Zhu ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Vortex Dynamics ◽  
Magnetization Relaxation

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.

scholarly journals Critical current density, vortex dynamics, and phase diagram of single-crystal FeSe

2015 ◽  
Vol 92 (14) ◽  
Author(s):  
Yue Sun ◽  
Sunseng Pyon ◽  
Tsuyoshi Tamegai ◽  
Ryo Kobayashi ◽  
Tatsuya Watashige ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Critical Current Density ◽  
Single Crystal ◽  
Critical Current ◽  
Current Density ◽  
Vortex Dynamics

Critical current density and vortex dynamics in pristine and proton-irradiated (Ba,K)Fe2As2

2013 ◽  
Vol 494 ◽  
pp. 106-108 ◽  
Author(s):  
Toshihiro Taen ◽  
Takahiro Ohori ◽  
Fumiaki Ohtake ◽  
Tsuyoshi Tamegai ◽  
Kunihiro Kihou ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Vortex Dynamics

Critical current density and vortex dynamics in uranium irradiated Co-doped BaFe2As2

2011 ◽  
Vol 471 (21-22) ◽  
pp. 790-793 ◽  
Author(s):  
H. Yagyuda ◽  
Y. Nakajima ◽  
T. Tamegai ◽  
Y. Kanai ◽  
T. Kambara
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Vortex Dynamics ◽  
Co 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.

Enhanced Vortex Pinning and Critical Current Density in Proton-Irradiated YBa2Cu3O7-δ Thin Films

1992 ◽  
Vol 279 ◽  
Author(s):  
E. L. Venturing ◽  
M. P. Siegal ◽  
A. E. White ◽  
S. Y. Hou ◽  
Julia M. Phillips
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Epitaxial Films ◽  
Vortex Pinning ◽  
Ex Situ ◽  
Relaxation Data ◽  
Magnetization Relaxation ◽  
Pinning Potential

ABSTRACTThe appropriate fluence of 2.0 MeV H1 ions has been shown previously to enhance the critical current density Jc by a factor of two at a magnetic field of 0.9 tesla in 1000 Å thick epitaxial films of YBa2Cu3O7-δ grown by the ex situ BaF2 process. The as-grown films exhibit single crystal-like behavior in both atomic ordering and Jc versus temperature and magnetic field. TRIM simulations suggest that H+ irradiation generates mainly point delects throughout the crystal structure. We show here that such defects result in an even greater enhancement of Jc for fields above 1 tesla plus a significant increase in the apparent vortex pinning potential deduced from magnetization relaxation data.

Critical current density and vortex dynamics in pristine and proton-irradiated Ba0.6K0.4Fe2As2

2015 ◽  
Vol 28 (8) ◽  
pp. 085003 ◽  
Author(s):  
Toshihiro Taen ◽  
Fumiaki Ohtake ◽  
Sunseng Pyon ◽  
Tsuyoshi Tamegai ◽  
Hisashi Kitamura
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Vortex Dynamics
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