Flux pinning in (Re)Ni2B2C superconductors
UNSPECIFIED (1999) Flux pinning in (Re)Ni2B2C superconductors. In: NATO Advanced Study Institute on Physics and Materials Science of Vortex States, Flux Pinning and Dynamics, KUSADASI, TURKEY, JUL 26-AUG 08, 1998. Published in: PHYSICS AND MATERIALS SCIENCE OF VORTEX STATES, FLUX PINNING AND DYNAMICS, 356 pp. 265-280.Full text not available from this repository.
Global and local magnetisation and transport resistivity measurements have been made on single crystals of the magnetic superconductor HoNi2B2C. Re-entrant or suppressed superconductivity is observed due to the onset of an a-axis incommensurate ordering of the Ho moments resulting in a strong suppression of B-c2 between temperatures of about 5 K and 6 K. Hysteresis in the global magnetisation is rather weak and asymmetric at all temperatures below T-c (similar to 8.9 K) suggesting that bulk pinning is weak and that surface and/or geometrical barrier effects are important. The form of the hysteresis curves at different temperatures is examined using a scaling analysis allowing regimes of similar pinning or surface barrier determined behaviour to be identified. Increased symmetry of the hysteresis is observed between 5 K and 6 K, coinciding with a sharp decrease in the flux flow resistivity. This suggests an increase in bulk pinning between these temperatures. We support our results with recent local magnetisation measurements made using a miniature linear Hall probe array. Measured flux profiles confirm the dominance of surface barriers over most of the phase diagram below T-c, except in the narrow temperature range between similar to 5 K and 6 K where bulk pinning becomes important. The data presented show that the competing effects of superconducting and magnetic order also have a profound influence on the vortex pinning properties of the superconducting state.
|Item Type:||Conference Item (UNSPECIFIED)|
|Series Name:||NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES E, APPLIED SCIENCES|
|Journal or Publication Title:||PHYSICS AND MATERIALS SCIENCE OF VORTEX STATES, FLUX PINNING AND DYNAMICS|
|Editor:||Kossowsky, R and Bose, S and Pan, V and Durusoy, Z|
|Number of Pages:||16|
|Page Range:||pp. 265-280|
|Title of Event:||NATO Advanced Study Institute on Physics and Materials Science of Vortex States, Flux Pinning and Dynamics|
|Location of Event:||KUSADASI, TURKEY|
|Date(s) of Event:||JUL 26-AUG 08, 1998|
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