DPG Phi
Verhandlungen
Verhandlungen
DPG

Dresden 2014 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 17: Superconductivity: Tunnelling, Josephson Junctions, SQUIDs

TT 17.4: Talk

Monday, March 31, 2014, 15:45–16:00, HSZ 201

Hybrid superconducting magnetic tunnel junctions: Coexistence of TMR and Josephson effects — •Ondrej Vavra1, 2, Rohit Soni2, Nico Ruppelt2, Adrian Petraru2, Hermann Kohlstedt2, and Christoph Strunk11Institute for Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany — 2Nanoelektronik, Technical Faculty, University of Kiel, D-24143 Kiel, Germany

We report on the latest results observed on hybrid superconducting SFIFS Josephson junctions with ferromagnet thickness-wedge (F). The Nb-Fe-Al2O3-Fe-Nb junctions were deposited by means of dc-magnetron sputtering technique. Junctions exhibit both Josephson effect and tunneling magnetoresistance (TMR) effect. Fraunhofer magnetic field dependence of the critical current IC(B) proves the homogeneity of the barrier over the 4 inch wafer. The properties of the junctions such as IC, normal conductance Gn and the tunneling magnetoresistance (TMR), respectively, strongly dependent on the oxidation parameters of the barrier (Al2O3). The different thickness of intermediate Al gives rise to the over- or under-oxidation, resulting in the Nb-Fe-Fe*-Al2O3-Fe-Nb or the Nb-Fe-Al-Al2O3-Fe-Nb, respectively. The layers denoted as Fe* (by oxygen affected Fe) and Al (residual Al layer underlying the Al2O3) are considered as parasitic since they suppress TMR. The impact of different thickness of both ferromagnetic layers dF on density of states, TMR and Josephson effect will be presented too.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2014 > Dresden