Controlled Pinning in Superconducting Foils by Surface Microgrooves

Abstract

To test the idea that surface irregularities can pin fluxons, regular parallel microgrooves were created in the surfaces of homogeneous cast In-2% Bi foils by pressing diffraction gratings into the foils. The pinning force thus induced was zero for flux flow parallel to the grooves and a maximum for perpendicular flux flow; a very simple dependence on the spacing and strength of the pinners was found.