L10 ordering and microstructure of FePt thin films with Cu, Ag, and Au additive

The influence of Cu, Ag, and Au additives on the L1(0) ordering, texture, and grain size of FePt thin films has been examined. Lattice parameter data indicated that Au and Ag additives tended to segregate from FePt, but Cu alloyed with FePt. FePt films with Au or Ag additive showed 1-2 kOe higher coercivity values compared to a pure FePt film after annealing at 450 degreesC and above for 10 min. The addition of at least 20 vol. % Cu to FePt boosted average coercivity values and increased (001)/(002) x-ray peak intensity ratios, suggesting an accelerated L1(0) ordering process for annealing temperatures exceeding 350 degreesC. Decreasing the film thickness promoted (001) film texture in FePt+20% Cu films, but higher annealing temperatures were required to achieve large coercivity. Au and Ag limited the average grain size compared to a pure FePt film. Cu additive increased the average grain size and film roughness. (C) 2002 American Institute of Physics.