Magnetic properties and microstructure of FePt/Ag2Te particulate films

Abstract

The [FePt(1 nm)/X(t)]10 (X=Ag2Te, Ag, and thickness of t=0.1–0.3 nm) multilayer was deposited alternately on glass substrate and subsequently annealed by rapid thermal process (RTP) at 800 °C for 10 min. After RTP, the interface between FePt and Ag2Te was intermixed by forming particulate films. The L10 FePt grain size decreases from 18 to 13 nm as t of Ag2Te intermediate layer increases from 0.1 to 0.2 nm. The (FePt/Ag2Te)10 particulate film shows perpendicular magnetization and out-of-plane coercivity increases with original Ag2Te thickness. As compared with (FePt/Ag2Te)10, the (FePt/Ag)10 multilayer is a continuous film after RTP. The Ag layer reduces ordering temperature of FePt but facilitates its grain growth during RTP. The [FePt/Ag(0.3 nm)]10 multilayer is magnetically isotropic as evidenced from magnetic hysteresis loops. Both Ag2Te and Ag atoms were immiscible with FePt phase but the FePt grains are refined and well-separated by Ag2Te phase.