  Magnetization and magnetoresistivity studies of Fe/V (001) superlattices are
reported. The first giant magnetoresistance peak with respect to the vanadium
and iron layer thicknesses is investigated. The interlayer antiferromagnetic
coupling strength is found to show a peak at a vanadium layer thickness of
  13 atomic monolayers ($\approx$ 20 \AA) with a full width at half maximum of
about 2 monolayers. The antiferromagnetic coupling shows a maximum at an iron
layer thickness of about 6 monolayers ($\approx$ 9 \AA) for series of
superlattices with vanadium thicknesses around 13 monolayers. The magnitude of
the giant magnetoresistance shows a similar variation as the antiferromagnetic
coupling strength.
