Anisotropic Magnetoresistance and Hall Effects for Ni-Co Alloy Thin Films

The relationship between anisotropic magnetoresistance and the Hall effect was studied for fcc Ni-Co binary alloy thin films. The maximum value of Δρ/ρ
₀
was 5.3%, obtained for 75 at % Ni-Co alloy. At this alloy composition, the ordinary Hall coefficient R
₀
was -2.0×l0
^~12
V- cm/A-Oe, and the extraordinary Hall coefficient R3 was 0.6×10
^-10
V-cm/A-G, or very nearly zero. It was also found that the magnetic moment per atom was 0.9μ
B
LB at this same alloy composition. All these relationships were found to be nearly the same as for Ni-Fe alloys. These results suggest that a large value of Δρ/ρ
₀
can be obtained in fcc Ni-base alloys under the following conditions: (1) when R
₀
is negative-valued and its absolute value is large, (2) when R
_s
is close to zero, and (3) when the magnetic moment per atom is 0.9μ
_B
.