Low-temperature in-situ growth of high-coercivity Fe-Pt films

摘要

[[abstract]]FePt films being with high coercivity, large energy product and corrosion resistance, are highly potential in applications such as MEMs, ultra-high density magnetic recording, and others. Much attention has been paid to the preparation of high quality films at substrate/annealing temperatures as low as possible to accommodate processing adopted in the manufacture of MEMs or sensors. In this study FexPt1-x thin films were deposited by DC magnetron sputtering onto Si(100) and CrMo-seeded glass substrates at a substrate temperature (Ts) 30 to 600 degreesC with or without further post-annealing. Optimum magnetic properties of our studied films were obtained at the Fe53Pt47 composition as-deposited at Ts 300 degreesC. The in-plane coercivity (Hc) is 8 kOe for as-deposited films on both Si(100) and glass, substrates. The films on Si(100) showed a maximum magnetization (M2T) and a maximum energy product of 950 emu/cm(3) and 15.8 MGOe, respectively. The squareness ratio (M-r/M-s) of the as-deposited FePt films on glass substrate increases with increasing Ts. Minor hysteresis loops reveal that domain-wall-pinning dominates the magnetic hardening of the FePt films. Post annealing at 400 degreesC substantially enhances coercivity and energy product for the Fe53Pt47 films on glass substrate. Ordering parameters were studied by XRD and quantitatively correlated to magnetic properties.