Formation of α-approximant and quasicrystalline Al-Cu-Fe thin films

[摘要] Multilayered Al/Cu/Fe thin films have been deposited by magnetron sputtering onto Si and Al2O3 substrates with a nominal global composition corresponding to the quasicrystalline phase, 5:2:1. Subsequent annealing was performed on the samples up to 710 degrees C. It is found that when using Si as a substrate a film-substrate reaction occurs already below 390 degrees C, where Si diffuses into the film. This changes the composition, promoting the formation of the alpha-approximant Al55Si7Cu25.5Fe12.5 in the temperature range 400 to 650 degrees C over the quasicrystalline psi-phase. When annealing the same Al-Cu-Fe thin film grown on Al2O3 substrates the Al62.5Cu25Fe12.5 icosahedral quasicrystalline phase is formed. (C) 2012 Elsevier B. V. All rights reserved.

[发布日期] 2012-12-30

[关键词] Quasicrystal;Approximant;Al-Cu-Fe-Si;X-ray diffraction;Annealing;Phase evolution;Multilayer;Sputtering