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arXiv · 1903.11150

Entropy jump at the first-order vortex phase transition in Bi2Sr2CaCu2O8+{\delta} with columnar defects

G. Rumi·L. J. Albornoz·P. Pedrazzini·M. I. Dolz·H. Pastoriza·C. J. van der Beek·M. Konczykowski·Y. Fasano
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Abstract

We study the entropy jump associated with the first-order vortex melting transition (FOT) in Bi2Sr2CaCu2O8+{\delta} crystals by means of Hall probe magnetometry. The samples present a diluted distribution of columnar defects (CD) introduced by irradiation with Xe ions. The FOT is detected in ac transmittivity measurements as a paramagnetic peak, the height of which is proportional to the enthalpy difference entailed by the transition. By applying the Clausius-Clapeyron relation, we quantify the evolution of the entropy jump {\Delta}s as a function of the FOT temperature, TFOT, in both pristine crystals and crystals with CD. On increasing the density of CD, {\Delta}s decreases monotonically with respect to values found in pristine samples. The {\Delta}s versus TFOT dependence in the case of pristine samples follows reasonably well the theoretical prediction of dominant electromagnetic coupling for a model neglecting the effect of disorder. The data for samples with a diluted distribution of CD are not properly described by such a theoretical model.

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G. Rumi, L. J. Albornoz, P. Pedrazzini, M. I. Dolz, H. Pastoriza, C. J. van der Beek, M. Konczykowski, Y. Fasano. 2019-03-26. Entropy jump at the first-order vortex phase transition in Bi2Sr2CaCu2O8+{\delta} with columnar defects. https://arxiv.org/abs/1903.11150

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