Oscillating magnetoresistance of Co/Cu(111) films

For two-layer Co(134A)/Cu(111) films on mica, obtained by e-beam evaporation, room temperature giant oscillations of resistance and the magnetroesistance (MR)(highest MR ratio--8.9%) were discovered as functions of Cu film thickness (t sub Cu ) in the range t sub Cu < =230A, where the Cu film had an island-type structure. The high MR ratio ( > =1.5%) was preserved up to t sub Cu < =850A. The separation distances of the resistance and MR extrema are multiples of the length 6.25A, which is practically equal to the spatial [111] diagonal of Cu unit cell. The resistance and MR oscillations are caused by the ordered variations of the geometric characteristics of island Cu films, induced by changing of the contact resistance of Cu-Co interfaces.