No abstract

An approximate 3-D micromagnetic model of a shielded, flnite stripe height, dual element Magnetoresistive head is developed. It is shown that asymmetric bias proflles in the cross track direction arise from uniform bias magnetic flelds. These asymmetric bias proflles appear in addition to the previously reported anisotropic signal flux propagation that occurs with respect to MR sensor width edges. In addition, A0 contours and track proflle response curves that arise due to simulated recorded magnetization signal flelds are presented.

The temperature and spacer-layer thickness dependences of the free layer coupling field in spin valves having Co 90 Fe 10 /Cu/Co 90 Fe 10 pinned-/spacer-/free layer trilayer structures have been measured. Our data verify a previously made theoretical prediction that the coupling field depends on both the shape of the Fermi surface of the spacer layer and the degree of confinement of the magnetic carriers in the spacer quantum well. In weakly confining systems such as Co 90 Fe 10 /Cu/Co 90 Fe 10 the latter mechanism can be large in the temperature range of interest and can have a significant impact on the temperature and spacer-layer thickness dependence of interlayer coupling fields. Including both mechanisms we are able to quantify the contribution of both the oscillatory interlayer and the Néel coupling field as well as the temperature-dependent data for the phase of the oscillations.

No abstract

The effect of a magnetic trailing shield located in close proximity of the pole tip for a perpendicular write head has been studied in a perpendicular recording system. For a 150nm wide write pole, the write field gradient is improved yielding a 40% decrease in jitter and 2.2dB increase in the signal-to-noise ratio (SNR). As the pole width is narrowed further, modeling and experiments show that the trailing shield leads to a tradeoff between maintaining a high write field (writeability) and achieving an optimal write field gradient (jitter). For a 70nm writer, the addition of a trailing shield results only in a small 0.5dB SNR gain despite a 25% decrease in jitter as a result of the concomitant loss in writeability. The latter results in an increased dc noise and becomes more significant with trailing shield throat thickness.