A hard bias (HB) structure for biasing a free layer in a MR sensor within
a magnetic read head is comprised of a main biasing layer with a large
negative magnetostriction (.lamda..sub.S) value. Compressive stress in
the device after lapping induces a strong in-plane anisotropy that
effectively provides a longitudinal bias to stabilize the sensor. The
main biasing layer is formed between two FM layers, and at least one AFM
layer is disposed above the upper FM layer or below the lower FM layer.
Additionally, there may be a Ta/Ni or Ta/NiFe seed layer as the bottom
layer in the HB structure. Compared with a conventional abutted junction
exchange bias design, the HB structure described herein results in higher
output amplitude under similar asymmetry sigma and significantly
decreases sidelobe occurrence. Furthermore, smaller MRWu with a similar
track width is achieved since the main biasing layer acts as a side
shield.