Abstract: The influence of the presence of Ag-layers on the formation of the ordered fct-L10 phase and the consequence of magnetic properties have been studied, when thin FePt films were deposited on glass and MgO substrates. It has been found that the presence of Ag layer (particularly Ag top-layer) can promote the formation of the high-coercivity fct-L10 phase. Epitaxial growth of the FePt (001) film was observed and the crystalline size is around 10 nm with a deposition temperature of 400$^{\circ}$C, when FePt thin film was deposited on MgO (100) single crystal substrate. With ultrathin Ag intermediate layers deposited between FePt layers, the surface morphology changed from interconnection network to isolated-island character. The perpendicular coercivity of the FePt film dramatically increased from 6.5 to 32.5 kOe.

Key words: High-density magnetic recording, FePt thin film...