Author:J. ABarrowa, V Fournée, AR Ross, PA Thiel, M Shimoda, AP Tsai
Institute: Department of Chemistry, Iowa State University, 225 Spedding Hall, Ames, IA 50011, USA, Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
Photoemission studies of sputter-induced phase transformations on the Al–Cu–Fe surface are an important aspect of studying multicomponent alloys, where the interaction between elements plays a decisive role in the formation of the microstructure. The experiment uses photoemission spectroscopy to analyze the electronic states and determine the reactions occurring on the surface of the selected material.
During sputtering, new phases are formed, which leads to a change in the electronic properties and, as a consequence, the physical and chemical properties of the alloy. Research shows that during sputtering, phase separation occurs, which may be due to the different bond energies between aluminum, copper and iron. Spectral analysis allows us to identify characteristic peaks corresponding to electron transitions and, thus, clarify the mechanism of formation of new phases.
This transformation is associated with a decrease in the spectrum intensity at the Fermi level, while the quasi-crystalline composition and X-ray photoelectron spectroscopy are used to examine the surface. The sputtered surface has a characteristic and chemical composition comparable to the cubic β-Al–Cu–Fe phase, as well as a sharp Fermi limit. With increasing annealing temperature, the surface structure and composition return to the state associated with electron diffraction. We investigated the surface of the icosahedral (i) Al–Cu–Fe quasi-crystalline sample as a function of annealing temperature using ultraviolet photoemission spectroscopy (UPS) and high-energy reflectance electrons.
Quasicrystals are unique solids with long-range order and no periodicity, exhibiting unusual electronic and thermal properties such as low adhesion and good oxidation stability. The electronic structure of these materials, both in the bulk and on the surface, is important for their physical properties and stabilization of the unique atomic structures. Incidentally, the pseudogap at the Fermi level provides increased stability by reducing the electronic contribution to the total energy of the system.
It is also important to note that such research contributes to the optimization of coating technologies and improvement of alloy characteristics. Understanding the processes occurring at the atomic level opens up new horizons for the development of materials with specified properties, which is key for many industrial applications.