Abstract
The ordering temperature of FePt films grown on PtMn underlayers was reduced due to phase transformation of the PtMn L 10 phase. The in-plane coercivity of 10 nm FePt on 50 nm PtMn underlayers was 7688 Oe after annealing at 325 °C. An exchange field of 554 Oe was also observed, which indicates that PtMn may not only induce the ordering of FePt at a reduced temperature, but also may provide extra anisotropy. A large coercivity of 10500 Oe can be achieved for 35 nm FePt films on PtMn underlayers after 325 °C annealing. © 2006 American Institute of Physics.