Ion-induced magnetic texturing of Ni films: Domain structure and strain

Ion-irradiation of ferromagnetic films induces pronounced changes of their microstructure and micromagnetism. The present study is devoted to the changes in the domain structure in 65–75 nm electron-evaporated polycrystalline Ni films due to 200-keV Xe+ or 100-keV Ni+ implantation. For magnetic analysis, we combined magnetic force microscopy (MFM) and magneto-optical Kerr effect (MOKE); X-ray diffraction and Rutherford back-scattering spectroscopy served to characterize the microstructure of the films. After deposition, MFM indicated a pattern of magnetic ripples (with in-plane and perpendicular components of the magnetization). After ion irradiation, MOKE showed almost total in-plane remanence, and MFM confirmed the disappearance of the ripples at room temperature. The magnetic properties were correlated with the ion-induced changes in the strain in the as-deposited and ion-irradiated films.