The Ag effect on magnetic properties and microstructure of FePt/Ag2Te particulate films

A [FePt (1 nm)/Ag2Te(t)]10 (thickness t = 0.1-0.3 nm) multilayer was deposited alternately on glass substrate and subsequently annealed by a rapid thermal process (RTP). After the RTP, the interface between FePt and Ag2Te was intermixed, forming particulate films. The L10 FePt grain size decreases from 23 to 14 nm as t of the Ag2Te intermediate layer increases from 0.1 to 0.3 nm. The (FePt/Ag2Te)10 particulate film shows perpendicular magnetization. Compared to (FePt/Ag2Te)10, the Ag/(FePt/Ag2Te)10/Ag multilayer also shows perpendicular magnetization with less c-axis dispersion. The Ag capping and seed layers reduce the ordering temperature of FePt but facilitate its grain growth during RTP. As a result, the FePt grains are refined and well-separated by the Ag2Te phase, but change to a continuous film after inserting Ag capping and seed layers.