SQUID investigations of Ga+ irradiated epitaxial Pt/Co/Pt trilayers

Spin reorientation transition in polycrystalline Pt/Co/Pt trilayers, i.e. rotation of the magnetization from an in-plane to out-of-plane orientation and vice versa can be precisely controlled by ion irradiation fluence [J. Jaworowicz et al., Appl. Phys. Lett., 95 (2009) 022502], similarly to the epitaxial Pt/Co/Pt trilayers exposed to 30 keV Ga+ ions in the fluence range of 1014-1016 ion·cm−2. Magnetic properties of a such irradiated system are studied by means of SQUID magnetometry. Zero field cooling and field cooling dependencies and also magnetization reversal curves are measured and analyzed in the frame of the Preisach model. The model explains structural and magnetic modifications occurring due to ion irradiation. A key magnetic properties, i.e. distribution of coercive and interaction fields, reversible and irreversible magnetic contributions are addressed. The interpretation of the results is also supported by the XRD synchrotron studies.