A magnetoresistive sensor having a novel seed layer that allows a bias
layer formed there over to have exceptional hard magnetic properties when
deposited over a crystalline structure such as an AFM layer in a partial
mill sensor design. The seed layer structure includes alternating layers
of Ru and Si and a layer of CrMo formed thereover. The seed layer
interrupts the epitaxial growth of an underlying crystalline structure,
allowing a hard magnetic material formed over the seed layer to have a
desired grain structure that is different from that of the underlying
crystalline layer. The seed layer is also resistant to corrosion,
providing improved sense current conduction to the sensor.