Investigations of the zero-field (a,b)-plane conductivity of YBa₂Cu₃O_7-δ near the critical temperature

Crisan, A., Gordeev, S.N., Manton, S., Rassau, A.P., Popa, S., Beduz, C., de Groot, P.A.J., Gagnon, R. and Taillefer, L. (1998) Investigations of the zero-field (a,b)-plane conductivity of YBa₂Cu₃O_7-δ near the critical temperature. Physica C: Superconductivity and its Applications, 309 (1-2), 1-7. (doi:10.1016/S0921-4534(98)00578-4).

Abstract

The resistive transition R(T) and the current–voltage characteristics (I–V) in the range 10^-9 – 10^-6 V and close to the critical temperature (T_c) were measured in a single-grain of melt-textured YBa₂Cu₃O_7-δ (YBCO) and in a detwinned YBCO single-crystal, with the transport current parallel to the (a,b) planes and in zero external magnetic field using a SQUID picovoltmeter. In the case of the melt-textured sample, we measured the I–V curves also at higher levels of dissipation. For T<T_c, we interpreted the lower part of the I–V curves in the framework of the Jensen–Minnhagen model of current-induced unbinding of thermally-created vortex–antivortex pairs, which leads to V ∝ I(I-I_c1)^a-1. Our results confirm a recently proposed current–temperature (I–T) phase diagram by S.W. Pierson. In addition, we determined for the first time the dependence of the characteristic (unbinding) current Ic1 with t = 1-T/T_c for temperatures very close to T_c and low transport currents.

This record has no associated files available for download.

Contributors

Download statistics