Spin‐wave resonance investigations of Ni‐ion implanted Permalloy films

Spin‐wave resonance (SWR) has been applied to investigate the influence of Ni‐ion implantation onto the magnetic properties of Permalloy films. The implantation has been carried out at room temperature with different doses at Ni‐ion energies of 95 keV. In films of 30–60 nm thicknesses, which are thin compared to the implantation range, with increasing dose the uniform mode is shifted to higher resonance fields in the parallel configuration. In the perpendicular configuration one obtains a shift to lower fields. The corresponding variation of the effective magnetization as a function of the implantation dose could be reproduced by assuming a change of the average volume magnetization. In thicker films (150–250 nm) standing spin waves are excited which are only slightly modified by implantation compared to the as‐prepared samples. The observed effects can be attributed to changes of the surface anisotropy.