Research Papers in Physics and Astronomy
Date of this Version
A sputtering gas-aggregation technique has been used to prepare FePt and FePt:Ag nanocluster films. The cluster size was controlled in a range from 3 to 6 nm. FePt cluster films were directly deposited onto Si substrate; FePt:Ag cluster films were fabricated by depositing a FePt cluster layer between a Ag underlayer and overlayer. Nanostructure and magnetic properties of the samples were characterized by x-ray diffraction, transmission electron microscopy, and magnetometry. The high magnetic anisotropy L10 fct phase was realized in the films annealed at a temperature of 550 °C and above. The orientation of clusters is random. The coercivity increases with an increase of annealing temperature; high in-plane and out-of-plane coercivities, exceeding 10 kOe, were achieved in both FePt and FePt:Ag cluster films after annealing. For FePt:Ag films, the coercivity increases with Ag underlayer thickness, tAg, and reaches about 17 kOe at room temperature for tAg = 5 nm after annealing at 650 °C for 10 min. The high coercivity is closely correlated with the degree of L10 ordering and nanostructure of the films.
Published by American Institute of Physics. J. Applied Physics 93, 8289-8291 (2003). ©2003 American Institute of Physics. Permission to use. http://jap.aip.org/jap/.