Interdiffusion in titanium permalloy thin films

This paper presents the results of investigation of interdiffusion in titanium permalloy thin film. It is found that interdiffusion in titanium-permalloy thin films is very detrimental to the magnetic properties of permalloy. Severe interdiffusion can take place with composite Ti/NiFe film annealed at 250°C for 90 minutes. Auger Analysis indicates the diffusion mechanism involves mainly Ni loss from the permalloy layer and diffusion into the Ti layer. Atmospheric exposure of the Ti layer before NiFe deposition can effectively control the interdiffusion process and prevent loss of magnetoresistive response. The x-ray diffraction data has indicated the formation of a Ni-Ti alloy to which may be attributed the degradation of the magnetic properties of Permalloy.