Isothermal I–V Curves Reconstruction in Superconducting Single Crystals by Means of Nonlinear AC Transport Experiments

Abstract

In this work, we propose a procedure to obtain the voltage vs current (I–V) curves bymeans of AC transport measurements, of particular interest for single crystals mountedon settings in which its thermal coupling to the environment is week, and Joule dis-sipation can cause unwanted thermal decoupling from the thermometer. We presenta simple model that accounts for the overheating of a sample in this type of exper-imental setup and propose two experimental protocols in which thermal oscillationsand gradients on the measured region of the sample can be neglected and the overalltemperature shifts can be accounted for and corrected. As an example, we presentpreliminary results obtained using one of these protocols in a Ba(Fe0.81Co0.09)2As2single crystal, mounted on a strain-cell, demonstrating that we are able to obtain reli-able I –V curves in the vicinity of a vortex-glass transition that exhibit the expectedcritical behavior. Both the model and the proposed procedure can be used in a broadspectrum of experimental situations far away the presented example.