Characteristics of strong ferromagnetic Josephson junctions with epitaxial barriers
Characteristics of strong ferromagnetic Josephson junctions with epitaxial barriers
We present the measurement of superconductor/ferromagnetic Josephson junctions, based on an epitaxial Nb bottom electrode and epitaxial ${\mathrm{Fe}}_{20}{\mathrm{Ni}}_{80}$ barrier. Uniform junctions have been fabricated with a barrier thicknesses in the range $2--12\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. The maximum critical current density $\ensuremath{\sim}2.4\ifmmode\pm\else\textpm\fi{}0.2\ifmmode\times\else\texttimes\fi{}{10}^{9}\phantom{\rule{0.3em}{0ex}}{\mathrm{Am}}^{\ensuremath{-}2}$ was found for a device with a $3\text{\ensuremath{-}}\mathrm{nm}$-thick barrier at $4.2\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, corresponding …