Co-Deposition of FePt and FePt/Ag Nanoparticles on Silicon Dioxide

The aim of the present study is to deposit FePt nanoparticles on SiO₂/Si substrates using Ag nuclei to investigate their crystallographic, morphological and magnetic effects on the alloy nanoparticles, and consequently, the enhancement of their coercivities which are excellent candidates for high-density recording media. FePt and FePt/Ag nanoparticles were prepared by electron beam evaporation by co-deposition on thermally oxidized silicon (100) substrates with a SiO₂ amorphous layer of 100 nm on top. The nanoparticles were annealed in-situ at 700degC immediately after the deposition for 5 minutes and showed maximum coercivity. The structural and morphological properties of the samples were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The magnetic properties of the FePt and FePt/Ag nano-islands were measured out of the substrate plane using a magneto optical Kerr effect magnetometer at room temperature.