Probing interface magnetism in the FeMn/NiFe exchange bias system using magnetic second-harmonic generation

Abstract

Second harmonic generation magneto-optic Kerr effect (SHMOKE) experiments,\nsensitive to buried interfaces, were performed on a polycrystalline NiFe/FeMn\nbilayer in which areas with different exchange bias fields were prepared using\n5 KeV He ion irradiation. Both reversible and irreversible uncompensated spins\nare found in the antiferromagnetic layer close to the interface with the\nferromagnetic layer. The SHMOKE hysteresis loop shows the same exchange bias\nfield as obtained from standard magnetometry. We demonstrate that the exchange\nbias effect is controlled by pinned uncompensated spins in the\nantiferromagnetic layer.\n