Exchange bias in Fe/KNiF3 bilayers

The exchange bias effect is known to depend strongly on the condition of th e ferromagnet/antiferromagnet interface. Bilayers of single-crystal Fe and polycrystalline KNiF3 were grown and exchange bias observed using supercond ucting quantum interference device magnetometry. Hysteresis loops after fie ld cooling are asymmetric in the forward and reverse directions. This asymm etry disappears at 50 K, indicating a blocking temperature for the bias wel l below the Neel temperature of KNiF3 (250 K). (C) 2001 American Institute of Physics.