Fabrication and nanostructure of oriented FePt particles

Thin films of oriented tetragonal FePt particles separated by amorphous alu mina 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. T he perpendicular magnetic coercivity of the annealed film was slightly larg er than in-plane coercivity. Some of the tetragonal FePt particles were fou nd to have {111} twins and stacking faults. From our high-resolution electr on microscopy observations, it was determined that central region of the or dered FePt particles tended to have c-axis perpendicular to the film plane. (C) 2000 American Institute of Physics. [S0021-8979(00)46908-2].