I have a CoFe/FeMn thin film, in which exchange bias has been induced by a field cooling. Can I remove the exchange bias (EB) of the film. Note that it was having a negligible EB in as deposited state.
Can I use the method used for demagnetization of the sample, i.e. submit it to successive cycles with smaller and smaller fields: [-Hmax(i), +Hmax(i)] i=1,2...,N , under the conditions H max(N)
When the FeMn film is thick enough that the EB is stable, you will not be able to remove it via field cycling. If your EB shrinks upon field cycling, you call this "training effect"; you might want to read up on this. Actually, the stability of EB is its beauty and why it is why it's so useful in certain applications. To remove the EB, you will have to heat the film beyond its blocking temperature (not Néel temperature, see O'Grady et al., J. Magn. Magn. Mater. 322, 883 (2010)) and cool without a field. A simple hot plate might be sufficient for FeMn, given that the stack is chemically stable in air. But be aware that this is, strictly speaking, not an EB-free situation. Instead, you just get a random distribution of EB orientations on a per-grain level. This is the mechanism behind the huge coercivity enhancement in the as-deposited state. Sometimes you might also see a kind of double-loop with two shifts in opposite directions in the as-deposited state, for the same reason.
cycling like demagnetisation should work only for residual field of machine. You may work with training effect and thickness of F layer.
If you just want to get rid of the hysteresis shift, but not necessarily of the increased coercive field, you may try rotating the sample by 90°. Depending on the crystallinity of the system and the FC orientation with respect to the easy axes, there may be a position in which the EB vanishes.
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