X-ray photoelectron spectroscopy studies of Ti-Al and Ti-Al-V alloys using CrKβ radiation

High-energy and conventional x-ray photoelectron spectroscopy (XPS) using Cr K-beta (hv = 5946.7 eV) and Al K-alpha (hv = 1486.6 eV) radiation, respectively, were employed to study the alloying behaviour of Ti with Al and V in Ti-Al (Al = 10, 20 and 30 at.%), V-50at.%Al, Ti-35at.%Al-15at.%V, Ti-40at.%Al-20at.%V, Ti-25at.%Al-25at.%V and Ti-50at.%V alloys. The differences of the initial and final state Auger parameters of the elements of interest between unalloyed and alloyed conditions were used to interpret possible charge transfer/redistribution between the elements and to explain subsequent electronic changes occurring upon alloying. The spectroscopic studies were related to thermodynamic predictions and the microstructures of the alloys. The large negative shift of the Al Auger parameter indicated that Al atoms are better screened in the pure metallic environment than in the alloy. This shift was attributed also to the ordering tendency in the Ti-Al and Ti-Al-V alloys, shown by thermodynamic modelling and microstructural studies. Variations of the initial state Auger parameter indicated that initial state effects are significant and may indicate charge transfer from the Al sites towards the transition metal sites. The Auger parameter variations of the transition metals were small, which is in agreement with previous studies. Copyright (C) 2001 John Wiley & Sons, Ltd.