Anisotropic magnetoresistance and Hall effects for Ni-Fe-M alloy thin films

The anisotropic magnetoresistivity, Δρ, and resistivity, ρ₀, were measured and related to the ordinary Hall coefficient, R₀, and the extraordinary Hall coefficient, R_s, for Ni-Fe and (Ni_89.5Fe _10.5)_100-x M_x(x⩽10) alloy films (M=Al, Si, Co, Cu, Nb or Gd). From the experimental results, the value of Δρ was found to be strongly related to R_s. At R_s=O, Δρ reached its maximum value, 0.65 μΩ-cm, and ρ₀ reached a minimum of 16.91 μΩ-cm. Contrary to ρ₀, Δρ did not depend on the film properties such as grain size or lattice imperfection. The R₀ was -1.6×10^-12 V-cm/AOe at the maximum value of Δρ. Therefore, it is concluded that large values of the anisotropic magnetoresistivity ratio, Δρ/ρ₀, would be obtained in ferromagnetic metals and alloys which satisfy the conditions R_s=0 and R₀≃-1.6×10^-12 V-cm/AOe, simultaneously. It was also revealed that a magnetic moment value of 0.9 μ_B corresponded to large Δρ/ρ₀ and R_s=0