  We demonstrate a simple, low cost, magneto-transport method for rapidly
characterizing the magnetic anisotropy and anisotropic magneto-resistance (AMR)
of ferromagnetic devices with uniaxial magnetic anisotropy. This transport
technique is the analogue of magnetic susceptibility measurements of bulk
material but is applicable to very small samples with low total moment. The
technique is used to characterize devices fabricated from the dilute magnetic
semiconductor (Ga,Mn)As. The technique allows us to probe the behavior of the
parameters close to the Curie temperature, in the limit of the applied magnetic
field tending to zero. This avoids the complications arising from the presence
of paramagnetism.
