|Typical material parameters as used for the calculation of the previous hysteresis curves are:|
|F thickness||tF||=||10 nm|
|AF thickness||tAF||=||20 nm|
|Saturation magnetization||JS||=||1 T|
|F exchange constant||AF||=||1x10-12 J/m|
|AF exchange constant||AAF||=||0.5x10-13 J/m|
|Interface exchange constant||AAF-F||=||-1x10-12 J/m|
|AF anisotropy constant||K||=||105 J/m3|
|Thickness of the Ferromagnet
In accordance with experiments our model predicts a 1/tF behavior of the bias field as long as the ferromagnet is thicker than the domain wall width of about 10 nm (for the chosen parameters). Below 10 nm the bias field drops by more than one order of magnitude.
|Thickness of the Antiferromagnet
The antiferromagnetic film has to exceed a critical thickness to support exchange bias. Beyond it the behavior of the experimentally found bias field depends on the certain sample. We obtained that the hysteresis shift reaches a maximum, for these parameters at about 22 nm, and then falls off. The coercive field increases continuously.
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Mar. 05, 2003