A. Chaiken, T.M. Tritt, D.J. Gillespie, J.J. Krebs, P. Lubitz, M.Z. Harford, and G.A. Prinz, Naval Research Laboratory, Washington, DC 20375
Resistivity measurements have been performed as a function of
temperature (1-300K) and magnetic field (0-10T) on
antiferromagnetically coupled Fe-Cr-Fe sandwiches. Two types
of samples were studied: MBE-grown sandwiches deposited
epitaxially on the ZnSe (100) surface, and evaporated
polycrystalline sandwiches deposited on glass substrates. The
magnetic saturation field Hs determined from the resistivity
r(H,T) is linear with temperature throughout the full
temperature range for all samples. In the polycrystalline
sandwiches, where the observed in-plane magnetic anisotropy
is small, the linearity of Hs(T) implies that the
antiferromagnetic interlayer exchange coupling A12 is also
linear with temperature. The magnetoresistance of the
sandwiches is constant at low temperature, and decreases
linearly with increasing temperature above about 70 K.