Figure 1: Magnetoresistance data with H along a [110] direction for an MBE-grown Fe-Cr-Fe sandwich with a 16Å Cr layer. Here the magnetoresistance Dr/r(%) is defined to be 100*[r(H=Hs)- r(H=0)]/r(H=0). The solid-headed arrows indicate the orientation of the moments of the two Fe films at a given applied field. The positions of the characteristic fields HJ and Hs are indicated.