Fabrication and characterization of CoZrGd Hall sensors

Thin films of the amorphous ternary alloy CoZrGd are deposited by single target magnetron RF sputtering. The Hall effect was studied as a function of Gd percentage. The amorphous films show unusually large spontaneous Hall effect, whose sign is strongly dependent on the film composition, as explained by the model of McGuire et al. Also, the films display perpendicular easy axis anisotropy, which significantly reduces the field needed to obtain technical saturation of the spontaneous Hall effect. Thus the sensitivity of the films can be substantially increased. The highest magnetic field sensitivity (-14.8%/Tesla) is accomplished with Hall angle (/spl rho/H//spl rho/) of -2.07% at a saturation field of 0.14 Tesla. This film has potential application in small fields.