Article thumbnail
Location of Repository

Flux pinning in (Re)Ni2B2C superconductors

By 

Abstract

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

Topics: Q
Publisher: SPRINGER
OAI identifier: oai:wrap.warwick.ac.uk:13890
Sorry, our data provider has not provided any external links therefore we are unable to provide a link to the full text.

Suggested articles


To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.