Recording limitations for SAL/MR and dual-stripe heads

A micromagnetic modeling analysis is performed to investigate the areal recording density limitations of the soft adjacent layer (SAL) biased and dual-stripe (DS) magnetoresistive recording head structures. The simulation analysis yielded four principle results: First, the higher output advantage of the DSMR head structure over the SAL head structure is largely due to the ohmic shunting loss of the SAL layer in the present SAL heads. Second, both the SAL and DSMR head structures are capable of supporting read track width as narrow as W=0.5 pm. Third, in order to support high linear densities, the spacing between the two MR stripes in the DSMR structure must be narrowed to obtain the adequate spectral response. There is, however, a corresponding amplitude reduction that is due to the magnetostatic interaction between the two stripes. Fourth, the track width broadening inherent in the DSMR structure when the two MR films are misaligned can be eliminated with a sense current inversion.