Tailoring of magnetism in Pt/Co/Pt ultrathin films by ion irradiation

Modification of Magnetic Properties of Pt/Co/Pt Films by Ga+ Ion Irradiation: Focused versus Uniform Irradiation

“…Using a wide range of ions fluence F (up to ion-driven nanostructure erosion) we have found some new phenomena, such as: (i) existence of two regions with increased magnetic anisotropy, usually connected with increased out-of-plane remnant magnetization, named "branch 1 and 2" in the (d Co , F ) phase diagram [22]; (ii) enhanced magneto-optical effects [21,22]. Two branches of increased magnetic anisotropy and enhanced Kerr rotation were observed after performing both Ga + and He + ions bombardment of Pt/Co/Pt [13].…”

“…The first goal of the present article is to compare the uniform 30 keV Ga + ion-irradiation-induced magnetic changes in Pt/Co(d Co )/Pt sputter-grown films with those ones previously reported for their MBE-grown counterparts [22], for both out-of-plane (d Co < d SRT ) and in-plane (d Co > d SRT ) magnetized pristine films [6]. Sputtering is an important technique of deposition of magnetic nanostructures.…”

“…1b), i.e. in the "branch 1" region [22], intermixing effects spread more and the composition of Co or Pt are different at the two buried interfaces.…”

“…Since few years, the influence of the uniform Ga + ions bombardment on properties of Pt/Co/Pt layers has been studied also for d Co > d SRT for nanostructures deposited by either sputtering [16][17][18] or molecular beam epitaxy (MBE) [19][20][21][22] techniques. Using a wide range of ions fluence F (up to ion-driven nanostructure erosion) we have found some new phenomena, such as: (i) existence of two regions with increased magnetic anisotropy, usually connected with increased out-of-plane remnant magnetization, named "branch 1 and 2" in the (d Co , F ) phase diagram [22]; (ii) enhanced magneto-optical effects [21,22].…”

“…X-ray absorption spectra (XAS), X-ray magnetic circular dichroism (XMCD), and extended X-ray absorption fine structure (EXAFS) techniques [17,20,22,23], as well as classical molecular dynamics and Monte Carlo simulations [24], were used for studies of Ga-ions-driven modification of Pt/Co/Pt structures. These changes in magnetic properties were interpreted by considering the competition between the interface and the bulk contributions, the last one being attributed to disordered or ordered CoPt alloys formation [22], lattice stresses [17,24] and Co-platelet formation [20]. Most of works were done on samples deposited by MBE technique.…”