Structure, magnetization, and thermal stability of (100) FeCu films deposited on Pd/Cu/Si(100)

Abstract

(100)-oriented FeCu films, containing 80 and 50 at. % Fe, have been deposited on (100) Si using (100) Pd/Cu seed layers. Heating of the samples helps identify the structures of the FeCu films, especially the one with 50 at. % Fe. The FeCu(50/50) film shows a structure with possibly two phases: one with a lattice spacing close to that of (100) Fe, and one to that of (100) Cu, henceforth assigned to the Fe- and Cu-stabilized FeCu phases, respectively. The FeCu(80/20) film shows only one phase, with a lattice spacing close to that of (100) Fe. Ferromagnetic characteristics are detected up to an anneal of 30 min at 600°C for the FeCu(80/20) films, with a reduced saturation magnetization above 400°C. For the FeCu(50/50) films, their ferromagnetic characteristics remain little changed up to 300°C, with reduced saturation magnetization at 400°C, and disappear completely after an anneal at 500°C. The results are compared with those containing elemental Fe layers deposited on different metal seeds, and the reaction mechanisms of the present structures are discussed.