Influence of the spreading resistance on the conductance spectrum of planar hybrid thin film SNS' junctions based on iron pnictides

11th European Conference on Applied Superconductivity

Döring, S.^1 ; Schmidt, S.^1 ; Gottwals, S.^1 ; Schmidl, F.^1 ; Tympel, V.^1 ; Mönch, I.^2 ; Kurth, F.^2 ; Iida, K.^2 ; Holzapfel, B.^2 ; Seidel, P.^1

Eriedrich-Schiller-University Jena, Helmholtzweg 5, Jena

07743, Germany^1

IEW Dresden, Helmholtzstr. 20, Dresden

01069, Germany^2

关键词: Conductance spectra;    Counter electrodes;    Empirical method;    Hybrid thin film;    Iron pnictides;    Spreading resistance;    Superconducting properties;    Thin-film technology;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/507/1/012008/pdf
DOI  :  10.1088/1742-6596/507/1/012008

来源: IOP

【 摘 要 】

To investigate the superconducting properties of iron pnictides we prepared planar hybrid SNS' junctions in thin film technology with a pnictide base electrode, a gold barrier layer and a lead counter electrode. Our design allows characterization of the electrodes and the junction independently in a 4-probe method. We show how both electrodes influence the measured spectra due to their spreading resistance. While the Pb electrode has a constant resistance above its Tc, the contribution of the pnictide electrode is clearly current-dependent and thus it needs a more advanced method to be corrected. We present an empirical method, which is simple to apply and allows to deal with the spreading resistance in our junctions to recalculate the actual conductance and voltage of one junction at given temperature.