Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1785493 | Current Applied Physics | 2016 | 18 Pages |
Abstract
We have investigated the influence of inter-vortex interactions on the critical current density (Jc) and flux pinning properties of single-crystalline MgB2 thin films grown using a hybrid physical-chemical vapor deposition system. Magnetic field dependences of Jc were measured over a 5-35 K range of temperatures for fields applied parallel and perpendicular to the ab-plane of the film's surface. Two regions along the Jc(H) curve, the low-field plateau region and the high-field slope region, which are respectively known as the single-vortex and collective pinning regimes, are clearly distinguishable. A ratio a0/λ between the inter-vortex spacing a0 and the penetration depth λ was calculated at each temperature, to investigate the effect of vortex-vortex interactions on the Jc(H). We found that the a0/λ dependences of the normalized Jc(H,T) data tend to fall onto one curve irrespective of the temperature, if only we use a certain average value of λ. Furthermore, the flux pinning mechanism shows a crossover from δTc-pinning to δl-pinning with increasing magnetic fields, indicating the coexistence of different pinning mechanisms in MgB2.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Duong Pham, Soon-Gil Jung, K.J. Song, M. Ranot, J.H. Lee, N.H. Lee, W.N. Kang,