0 avis
Modification of Co/Pt multilayers by gallium irradiation - Part 1: The effect on structural and magnetic properties
Archive ouverte
Edité par CCSD ; American Institute of Physics -
International audience. Atomic force microscopy, transmission electron microscopy, optical, and magneto-optical microscopy have been used to study how structural and magnetic properties are changed when a Co/Pt multilayer is quasihomogeneously irradiated with Ga ions. Under low irradiation fluence, both grain size and texture in the multilayer increase. These effects continue for fluences in excess of 1 × 1015 Ga ions/cm2, but beyond this dose significant thinning of the multilayer is also observed. Three distinct irradiation-induced magnetic regimes with sharp transitions between each were identified. For Ga fluences less than 5 × 1012 ions/cm2, the irradiated region retains perpendicular uniaxial anisotropy but with coercivity lower than that of the as-grown film. For fluences between 5 × 1012 and 1 × 1011 Ga ions/cm2, a transition from perpendicular to in-plane magnetization was experienced. Very little change of the in-plane magnetic properties of irradiated multilayers is then observed until the sample experiences a ferromagnetic to paramagnetic transition at fluences around 1 × 1015 Ga ions/cm2. A brief comparison with the effect of irradiating with He ions is given.