Noise measurements on NiFe/Ag multilayered structures

Noise in NiFe/Ag giant magnetoresistive (GMR) multilayers and in magnetic f ield sensors based on this material has been studied in order to evaluate t he potential of such material and such sensors for low field applications, GMR stripes were used to study the material intrinsic noise for varying de sense current density, applied field and device dimensions, Noise measureme nts were then carried out on a magnetic field sensor for which thermal and magnetic characteristics have also been studied, The noise in NiFe/Ag multilayers is dominated by a 1/f noise at low frequen cies and shows a flat spectrum at higher frequencies due to Johnson noise. The 1/f noise increases with the current density and is field and device-di mensions dependent. Magnetic field sensors based on NiFe/Ag are good candid ates for the realization of low field micromagnetometers because they have suitable characteristics and relatively low noise.