A structure for stabilizing the active region of the magnetic sensor comprises a hard ferromagnetic element adjacent to a biasing multilayer element placed on either side of the active region of the magnetic sensor. The biasing multilayer element includes soft ferromagnetic and anti-ferromagnetic layers such that the biasing strength applied to the active region of the magnetic sensor is tuneable by adjusting the length of the soft ferromagnetic layer or layers as well as the insertion of spacer layers between the soft ferromagnetic materials and the anti-ferromagnetic layers. The inventive structure provides longitudinal bias to the active region with improved domain control, signal amplitude and side-reading properties.