Abstract
Effects of the weak point disorder on the vortex matter phase diagram are studied by an irradiation of 2.5 MeV electrons in untwinned single crystals. We find that the point disorder lowers the critical point of the first-order vortex lattice melting line and has an opposite effect on the vortex glass phase boundary above and below Below the field-driven disordering transition line between the Bragg glass and the vortex glass phases shifts to lower fields and the vortex glass phase is expanded after irradiation. Near the vortex liquid-to-glass transition line above on the other hand, the vortex glass phase is reduced after irradiation, indicating the enhanced vortex wandering by the point disorder in the critical region.
- Received 25 May 1999
DOI:https://doi.org/10.1103/PhysRevB.61.3649
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