Magnetic and magnetotransport properties in epitaxial FeMn/Py/Cu/Py spin-valve films

We have studied magnetic and magnetotransport properties in fcc [111]- and (211)-oriented [FeMn/Py/Cu/Py](Py=Ni/sub 80/Fe/sub 20/) films grown on Mo[110] and Mo(211) templates by molecular beam epitaxy. Uniaxial magnetic anisotropy of the magnetic layers in both cases were self-assembled by epitaxial growth. However, the pinned layer coercive fields of the (211) films were much higher than those of the [111] samples. For both orientations the optimal exchange field (/spl sim/130 Oe) and magnetoresistance (/spl sim/3%) occur at substrate temperature of /spl sim/170/spl deg/C, about 30-40/spl deg/C above the blocking temperature of the FeMn layer.