Formation of the atomically ordered L10 structure with the [001] orientation during the solid-state reaction in Fe/Pd bilayer thin films

Abstract

The formation of the atomically ordered L1₀-FePd structure during the solid-state reaction in Fe/Pd bilayer thin films is in situ investigated by electron microscopy and electron diffraction analysis. The initial iron and palladium layers were mainly coherently oriented crystallites with the orientation relationship α-Fe (001)[110] || Pd(001)[100]. It is established that the solid-state reaction between the iron and palladium layers upon heating at a rate of 4–8°C/min starts with the formation of the FePd solid solution at 390°C; at 430°C, the formation of the atomically ordered L1₀-FePd structure is observed. It is shown that at the low heating rate (4–8°C/min), the L1₀-FePd structure with the [001] orientation relative to the film plane forms, while at the high heating rate (50°C/min) it forms with the [100], [010], and [001] orientations.