The microstructure of Co/Pt multilayers with large perpendicular
magnetic anisotropy (PMA) was investigated before and after
energetic ion irradiation. No pronounced microstructural changes
were detected at ion doses sufficient to completely reduce the
PMA and cause a spin reorientation transition to in-plane.
Ion-induced displacement of Co and Pt atoms near Co/Pt interfaces
lead to local “roughening” and Co layer strain
relaxation, reducing the PMA. The magnetic domain confinement
induced by ion irradiation and magnetic patterning by selective
ion irradiation were also investigated.