In this work, a study of the sensitivity enhancement of spin valve sensors, when located
in close proximity to magnetic flux guides, is presented. The magnetoresistance (MR) of spin-valve
sensors, lithographically patterned into stripes with lateral dimensions, (length) l = 500 µm, (width)
wsensor = 1, 2, 6 µm and placed near one/two Co93.5Zr2.8Nb3.7 (CZN) magnetic flux guide, is
characterized at room temperature. CZN has a high permeability that together with a defined
microstructured shape, is able to concentrate the magnetic flux in a small area, leading to an
increase in sensor's sensitivity. The magnetic field amplification is estimated by comparison of
sensor sensitivity with/without magnetic flux guides, in the linear operation range, and studied as a
function of different parameters. Besides an enhancement in sensitivity, sensors also exhibit an
important increase in the hard axis coercivity and a shift from MR(H=0) = 0.5, both attributed to the
magnetic flux guides. Amplification factors of the order of 20 are observed..
Magnetic flux in soft magnetic Fe-Si-B-P-Cu amorphous alloy containing nanocrystallites analyzed by electron holography
