Magnetic properties of a heavy-ion irradiated single crystalline iron film were investigated. A high quality Fe(001) film with a thickness of 250nm was fabricated on MgO(001) using the molecular beam epitaxy technique. The film was irradiated by 3.2MeV Ni ions at room temperature using a tandem accelerator. Formation of dislocation loops of nanometer size was observed by transmission electron microscopy observation, and that of sub-nanometer size vacancy clusters was confirmed indirectly by a resistivity increase. However, M-H hysteresis curves and magnetic domain structure did not change significantly. These results indicate the formation of irradiation defects of pure iron in nanometer scale range had little influence on the magnetization process of the iron.

Magnetic Properties of Ion Irradiated Epitaxial Fe Films. Y.Kamada, H.Watanabe, S.Mitani, J.Echigoya, J.N.Mohapatra, H.Kikuchi, S.Kobayashi, K.Takanashi: Journal of Physics - Conference Series, 2011, 266[1], 012035