Fabrication and nanostructure of oriented FePt particles

Thin films of oriented tetragonal FePt particles separated by amorphous alumina have been fabricated by electron beam evaporation. The ordering of the FePt particles without coarsening can be tailored by annealing conditions. The value of coercivity of the annealed film reached as high as 4.4 kOe. The perpendicular magnetic coercivity of the annealed film was slightly larger than in-plane coercivity. Some of the tetragonal FePt particles were found to have $111% twins and stacking faults. From our high-resolution electron microscopy observations, it was determined that central region of the ordered FePt particles tended to have c-axis perpendicular to the film plane. © 2000 American Institute of Physics. @S0021-8979~00!46908-2#