Artificial Grain Boundary Junctions in BiSrCaCuO Thin Films with (11n) and (001) Orientation

Abstract
Artificial grain boundary junctions in sputtered BiSrCaCuO films on SrTiO3 (110) substrates have been fabricated by controlling the orientation of the films using a MgO buffer layer. A grain boundary with large twist misorientation is formed along the edge of the MgO buffer layer that is placed perpendicular to the [001] direction of the SrTiO3 substrate. The grain boundary junctions thus obtained exhibited clear Shapiro steps in response to microwave irradiation (15.7 GHz). This indicates that the artificial grain boundaries obtained by controlling the orientation of the BiSrCaCuO films behave as a weak link.