Abstract:
Second harmonic generation magneto-optic Kerr effect (SHMOKE) experiments, sensitive to
buried interfaces, were performed on a polycrystalline NiFe/FeMn bilayer in which areas with different
exchange bias fields were prepared using 5 KeV He ion irradiation. Both reversible and
irreversible uncompensated spins are found in the antiferromagnetic layer close to the interface with
the ferromagnetic layer. The SHMOKE hysteresis loop shows the same exchange bias field as obtained
from standard magnetometry. We demonstrate that the exchange bias effect is controlled by
pinned uncompensated spins in the antiferromagnetic layer.
