Magnetic properties and microstructure of FePtB, FePt(B–Ag) granular films

Abstract Multilayers [FePt(1 nm)/B( t nm)] 10 ( t =0.05–0.6) were alternately deposited on a glass substrate and subsequently annealed by the rapid thermal process (RTP) at 800 °C for 3 min. After RTP, FePt and B layers intermix to form the FePtB film with (0 0 1) texture. The ordering degree of FePt was slightly increased with doped B. The (Fe–Pt) 100− x B x ( x =0, 5, 10) films show perpendicular magnetization and the minor FeB phase was indexed in isotropic (Fe–Pt) 100− x B x ( x =30, 40, 60) films. By adding Ag into (Fe–Pt) 95 B 5 film, the ordering degree was slightly increased in (Fe–Pt) 95 (B 0.9 Ag 0.1 ) 5 film. In (Fe–Pt) 100− x B x ( x =5, 10) and (Fe–Pt) 95 (B 0.9 Ag 0.1 ) 5 granular films, the intermixed B or Ag atoms were diffused among FePt grain boundaries to isolate and refine FePt grains uniformly with average grain sizes of 20, 15, and 6.7 nm, respectively.