Abstract
Abstract FeXPt1-X(x=46, 53, 55, 81) thin films were deposited by dc magnetron sputtering on Si(100) and CrMo-layer seeded glass substrates. The sputtering was carried out at high substrate temperatures to help direct formation of ordered phase γ1. Boron and nitrogen were added into some FePt films to realize their effects on structure and magnetic properties. Optimum magnetic properties of the films were obtained at composition of Fe53Pt47 at substrate temperature 300oC. It's in-plane coercivity (Hc) is about 8kOe and its saturation magnetization is around 950emu/cc; its (BH)max is 15.8MGOe. The squareness of the as-deposited FePt thin films increased as increasing substrate temperature. The magnetic hardening of FePt films was found to be controlled by domain wall pinning from the behavior of inner hysteresis loops. After post annealing at 400oC for 2 hours, the magnetic properties were Hc=2.7 kOe, (BH)max=18.5MGOe for the Fe53Pt 47 films. In the FePtBx alloy system, the degree of ordering was obviously increased at low substrate temperatures compared with FePt system, while no big difference was observed at higer substrate temperatures. In the FePtNx system, the in-situ nitrided films sputtered in a mixed Ar and N2 atmosphere showed decreasing coercivity as increasing N2 partial pressure . For post-nitrided films, there is a little expansion along c-axis. The coercivity increased while saturation magnetization decreased with increasing post-nitriding time.