Mictomagnetism is a spin system in which various exchange interactions are mixed. It is observed in several kinds of alloys, including Cu-Mn, Fe-Al and Ni-Mn alloys. Cooled in zero magnetic field, these materials have low remanence and coercivity. Cooled in a magnetic field, they have much larger remanence and the hysteresis loop is shifted in the direction opposite to the field (an effect similar to exchange bias).
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Mictomagnetism Wikipedia(Text) CC BY-SA