Exponential dependence of the vortex pinning potential on current density in high-Tcsuperconductors

2005 ◽  
Vol 72 (6) ◽  
Author(s):  
H. Yan ◽  
M. M. Abdelhadi ◽  
J. A. Jung ◽  
B. A. Willemsen ◽  
K. E. Kihlstrom
1992 ◽  
Vol 279 ◽  
Author(s):  
E. L. Venturing ◽  
M. P. Siegal ◽  
A. E. White ◽  
S. Y. Hou ◽  
Julia M. Phillips

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.


Nanoscale ◽  
2020 ◽  
Vol 12 (22) ◽  
pp. 12076-12082
Author(s):  
Xin He ◽  
Yan Wen ◽  
Chenhui Zhang ◽  
Zhiping Lai ◽  
Eugene M. Chudnovsky ◽  
...  

We investigate the transport properties of a NbSe2 step junction and verify that the enhancement of the critical current density is due to the vortex pinning at the step junction.


1994 ◽  
Vol 194-196 ◽  
pp. 1859-1860 ◽  
Author(s):  
W. Lang ◽  
C. Fussenegger ◽  
P. Schwab ◽  
X.Z. Wang ◽  
D. Bäuerle

2016 ◽  
Vol 7 ◽  
pp. 1698-1708 ◽  
Author(s):  
Ismael García Serrano ◽  
Javier Sesé ◽  
Isabel Guillamón ◽  
Hermann Suderow ◽  
Sebastián Vieira ◽  
...  

We report efficient vortex pinning in thickness-modulated tungsten–carbon-based (W–C) nanostructures grown by focused ion beam induced deposition (FIBID). By using FIBID, W–C superconducting films have been created with thickness modulation properties exhibiting periodicity from 60 to 140 nm, leading to a strong pinning potential for the vortex lattice. This produces local minima in the resistivity up to high magnetic fields (2.2 T) in a broad temperature range due to commensurability effects between the pinning potential and the vortex lattice. The results show that the combination of single-step FIBID fabrication of superconducting nanostructures with built-in artificial pinning landscapes and the small intrinsic random pinning potential of this material produces strong periodic pinning potentials, maximizing the opportunities for the investigation of fundamental aspects in vortex science under changing external stimuli (e.g., temperature, magnetic field, electrical current).


1997 ◽  
Vol 504 ◽  
Author(s):  
P. Newcomer Provencio ◽  
E. L. Venturini ◽  
B. L. Doyle ◽  
D. K. Brice ◽  
H. Schöne

ABSTRACTLattice defects are introduced into the structure to suppress the motion of magnetic vortices and enhance the critical current density in high temperature superconductors. Point defects are not very effective pinning sites for the cuprate superconductors; however, extended defects, such as linear tracks, have been shown to be strong pinning sites. We study the superconducting cuprate TI-2212 (the numbers designate Tl-Ba-Ca-Cu stoichiometry). Large enhancements of vortex pinning potential were observed in TI-2212 after high-intermediate energy heavy-ion irradiations where non-continuous extended defects were induced at dE/dx of 9 to 15.2 keV/nm (60 MeV Au, 60 MeV Cu, and 30 MeV Au) and continuous linear defects were induced at 19.5keV/nm (88MeV Au). Our research addresses the question of pinning in highly anisotropic materials like Tl-2212 where the vortices are “pancakes” rather than “rods” and suitable defect structures may be discontinuous extended damage domains. The defect microstructure and the effectiveness of the pinning potential in TI-2212 after irradiation by intermediate energy Au at lower dE/dx of 5–15 keV/nm, where recoils are more significant, is studied using high resolution transmission electron microscopy digital imaging and a SQUID magnetometer. The nature of the ion irradiation damage at these intermediate dE/dx will be correlated to the average vortex pinning potential and the TRIMRC calculations for recoils.


2007 ◽  
Vol 90 (25) ◽  
pp. 252502 ◽  
Author(s):  
S. I. Kim ◽  
F. Kametani ◽  
Z. Chen ◽  
A. Gurevich ◽  
D. C. Larbalestier ◽  
...  

2003 ◽  
Vol 68 (22) ◽  
Author(s):  
S. Y. Xu ◽  
Qi Li ◽  
E. Wertz ◽  
Y. F. Hu ◽  
A. V. Pogrebnyakov ◽  
...  

1996 ◽  
Vol 10 (10) ◽  
pp. 451-458 ◽  
Author(s):  
SUJAY DATTA ◽  
SHANTILAL DAS ◽  
DESHDEEP SAHDEV ◽  
RAVI MEHROTRA

We develop an algorithm based on the Fast Cosine Transform to study two-dimensional arrays of Josephson junctions containing defects. We apply it to arrays as large as 128 × 256 and study vortex pinning, the transition from the superconducting to the resistive state, and various finite size effects. We find that the pinning potential for vortices is highly anisotropic in rectangular arrays due to boundaries and finite size effects. As a result we observe pinned vortices in arrays much smaller than expected so far. The energy of an array changes discontinuously at transitions from one vortex sector to another in the steady-state regime.


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