Study of alloying behaviour in metastable Mg-Ti solid solutions using Auger parameter measurements and charge-transfer calculations

The Auger parameter in vapour-deposited Mg-Ti alloys (Mg-4.2at.%Ti, Mg-7.6at.%Ti, Mg-15.1 at% Ti, Mg-20.7 at.% Ti. Mg-25.3 at.% Ti and Mg-30.2 at.% Ti) has been measured using high-energy X-ray photoelectron spectroscopy with a Cr Kbeta (hnu = 5946.7 eV) X-ray source. The charge transfer occurring upon alloying was estimated using the Thomas-Weightman model. The data were used to investigate changes occurring in the electronic structure upon alloying. Changes in the Auger parameter of the Mg-Ti alloys suggested that, in contrast with Mg, Ti is better screened in the presence of a core hole in the alloy than in the pure form. The Mg-to-Ti charge transfer in the Mg-Ti alloys was smaller than in the Mg-V alloys studied previously. This is in agreement with the Pauling electronegativities of V and Ti.