MAGNETORESISTANCE EFFECT IN NON-MAGNETOSTRICTIVE NI-FE-CO FILMS

An investigation of the magnetoresistance effect in vacuum-evaporated non-magnetostrictive NiFeCo films in the compositional range 0-40 wt.% cobalt was made. The resistivity ρ{variant} and the magnetoresistance ratio Δρ{variant}/ρ{variant} were measured as a function of the composition, the substrate temperature during evaporation and the deposition rate. Δρ{variant}/ρ{variant} was found to be a maximum for the 30 wt.% cobalt alloy and was approximately twice the value obtained for 82 wt.% Ni18 wt.% Fe films. The variation of resistivity with substrate temperature was correlated with published data of the intrinsic stress, and the result is discussed in terms of grain boundary phenomena. Measurements of the decrease in resistivity on isothermally annealing films in the thickness range 0.14-0.16 μm were made. The results differ from the previously published data relating to thin (0.02 μm) NiFe films. © 1978.