First-order vortex transition with strong pinning centers

RUMI, G.; CORTÉS MALDONADO, R.; ARAGÓN SÁNCHEZ, J.; ALBORNOZ, L.J.; PASTORIZA, H.; PEDRAZZINI, P.; VAN DER BEEK, CORNELIS J.; KONCZYKOWSKI, M.; FASANO, Y.

Bariloche

Workshop; Póster en la YIELDING PHENOMENA IN DISORDERED SYSTEMS; 2019

Centro Atómico Bariloche - Instituto Balseiro

A rst-order phase transition takes place in superconducting vortex matter onhigh-temperature cuprates separating phases with diering shear modulii. Eachphase shows a different behaviour on the ux creep and the critical currents. Bymeans of magnetic decorations and Hall probe magnetometry we study the eectof a low concentration of strong pinning centers on the structural properties ofvortex matter and on the phase transition itself. Irradiated Bi2Sr2CaCu2O8+samples with columnar defects with matching elds of B_phi = 10; 30; 40; 60 and90 Gauss have been studied, revealing a clean, rst-order transition for thematching elds below 50 Gauss, turning into a glassy transition in samples withdenser disorder (B_phi = 60 and 90 Gauss). A comparison with structural prop-erties leads us to suggest that the in-plane positional order is not the symmetrybroken at the transition.1