The study of solid-phase reactions in thin-film AleCueFe systems is of considerable interest in the field of materials science and nanotechnology. Such systems find application in microelectronics, sensors and catalysis.
Thin films of AleCueFe obtained by magnetron sputtering were subjected to heat treatment in vacuum to initiate solid-state reactions. Structural changes and phase composition of the films were analyzed using X-ray diffraction and electron microscopy.
Many researchers have studied phase formation in Al-Cu-Fe thin film systems. However, these studies have mainly focused on the ternary composition corresponding to the icosahedral phase i-Al62.5Cu25Fe12.5. The uniqueness of this phase lies in its properties: surprisingly low electrical conductivity at room temperature, especially compared to typical aluminum-based alloys; surprisingly low thermal conductivity, more than two orders of magnitude lower than that of pure aluminum at room temperature; significant hardness, comparable to the hardness of high-strength steels; reduced surface energy and low friction coefficient.
Similarly, studies of the Al-Cu-Fe phase diagram have mainly focused on the aluminum-rich region near the icosahedral phases. Fodo proposed a subsolidus projection of the Al-Cu-Fe ternary diagram in this aluminum-rich region, which shows four ternary phases (a, u, i, 4) and eight ternary solid solutions derived from binary phases (l-FeAl3, m-Fe2Al5, y-FeAl2, b-AlFe, q-Al2Cu, h-AlCu, z-Al3Cu4, d-Al2Cu3). Other ternary phases may be useful in areas such as coatings or thermoelectric materials.
The aim of this study was to investigate the phase formation in Al/Cu/Fe thin film systems with a and u compositions. In addition, two additional samples, Al33Cu33Fe33 and Al15Cu55Fe30, were analyzed to explore less explored regions of the Al-Cu-Fe phase diagram. The samples were prepared by sputtering and characterized using in situ resistivity measurements, in situ X-ray diffraction (XRD), and differential scanning calorimetry.
It has been established that upon heating, diffusion of atoms between the AleCueFe layers occurs with the formation of intermetallic compounds. Temperature and annealing time have a significant effect on the kinetics of reactions and the composition of the resulting phases.
The obtained results allow controlling the structure and properties of AleCueFe thin films by controlling the thermal treatment parameters. This opens up prospects for creating materials with specified characteristics for various applications.
Author: Fanta Haidara, Marie-Christine Record, Benjamin Duployer, Dominique Mangelinck
Institute: IM2NP, UMR 6242 CNRS, Université Aix-Marseille, Av Escadrille Normandie-Niemen, Case 142, 13397 Marseille Cedex 20, France