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Fabrication of high quality ferromagnetic Josephson junctions

M. Weides·K. Tillmann·H. Kohlstedt
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Abstract

We present ferromagnetic Nb/Al2O3/Ni60Cu40/Nb Josephson junctions (SIFS) with an ultrathin Al2O3 tunnel barrier. The junction fabrication was optimized regarding junction insulation and homogeneity of current transport. Using ion-beam-etching and anodic oxidation we defined and insulated the junction mesas. The additional 2 nm thin Cu layer below the ferromagnetic NiCu (SINFS) lowered interface roughness and ensured very homogeneous current transport. A high yield of junctional devices with jc spreads less than 2% was obtained.

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M. Weides, K. Tillmann, H. Kohlstedt. 2005-11-22. Fabrication of high quality ferromagnetic Josephson junctions. https://doi.org/10.1016/j.physc.2005.12.046

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