Abstract
A 3-dimensional micromagnetic model was developed in order to study spin-valve (SV) heads with synthetic ferrimagnetic pinned layers (SF) and SV heads with bias compensation layers (BCL). All of these heads have three-magnetic layers. The magnetization angle change δθ in the free layer caused by the stray field from the medium was calculated for each SV head. When the sensor height is greater than 0.4 μm, δθ for the SV head with BCL is over 20% larger than for the SV head with SF, owing to the magnetic saturation in the BCL. When the sensor height decreases, δθ for the SV head with a BCL decreases because the BCL is not saturated, while δθ for the SV head with SF increases. The output efficiencies of the BCL-type head is almost the same as that of the SF-type head when each sensor height is adequate.
