Magnetic field sensing film (Ni0.81Fe0.19)0.66Cr0.34/Ni0.81Fe0.19

Anisotropic magnetoresistance (AMR) effect thin film sensor has a very wide prospect in application. In this paper, we studied the structure, the AMR and the size effect of the Permalloy film with (Ni0.81Fe0.19)0.66Cr0.34 layer as buffer layer. The resistance of NiFeCr is larger than that of Ta and has the same face-cubic structure as NiFe, which could depress the current shunting effectively and be benefit to the formation of the well-textured NiFe layer. The measurements of XRD and AFM showed that, the specimens with (Ni0.81Fe0.91)0.66Cr0.34 and Ta buffer have close surface roughness, while the former had more textured structure. (Delta) R/R decreased and the saturation field increased with the reduction of the width of the AMR stripes etched by ion beam. However, the magnetic field sensitivity could still reach 0.16 percent/Oe when the width reduce to 30micrometers , and could correctly respond to an alternative magnetic field.