摘要
The applications of low energy argon or oxygen ion-beam assisted deposition and high energy oxygen ion implantation for thin film fabrication and modification of the microstructural, compositional and magnetic properties are demonstrated. Five representative model systems are discussed with the state-of-the art characterization tools such as atomic force microscopy, X-ray diffraction, transmission electron microscopy and electron energy loss spectroscopy, X-ray synchrotron-based spectroscopy techniques, and SQUID magnetometry. For example, (i) in nanostructured Fe/Cu thin films, by tuning the amount of interfacial Fe-Cu alloy, the control of the magnetic ordering temperature and the nature of the nanocrystallite dynamical freezing processes have been achieved. (ii) In NiFe/NiO bilayers, the exchange coupling was enhanced when the interface roughness was reduced and the interface texture was changed to a striped configuration. (iii) [Pt/Co]/NiO multilayers could be grown so that the origin of perpendicular magnetic anisotropy was identified as coming from mixed CoPt phases driven by negative heat of mixing when Co thickness was reduced. (iv) In Mn/NiFe thin films, a structural phase transformation from Mn to MnO via ion implantation gave rise to the modifications that can determine the magnetic properties. (v) NiO/NiFe antidot arrays were made with a unidirectional bias that resulted in an induced asymmetric microwave response, which was linked to an unbalanced distribution of the demagnetizing fields around the hole edges.