Synthesis of L1_0 FePt nanograins at lower temperature by inserting FeAl underlayer

With inserted FeAl underlayer and MgO intermediatelayer,FePt thin films were sputtered on MgO(001) substrates.FeAl layer transforms into ordered B2 phase by annealing at temperatures of Ta ≥ 300°C,and has the flattest surface at Ta = 400°C,as the thermal vacancies do not concentrate on the surface.Due to the matching of lattice among MgO,FeAl and FePt,the epitaxially grown FePt films show obvious(001) textures.The FeAl underlayer significantly reduces the temperature for formation of ordered L10 FePt,and the MgO intermediatelayer effectively prevents from the interlayer diffusion.At a lower circumstance temperature of 400°C,L10 FePt grains with relatively uniform size of ～10 nm can be synthesized.The coercivity measured at room temperature is ～20 kOe.Such particular films have the potential application in perpendicular magnetic recording media.