ARXPS and high energy XPS characterisation of titanium surfaces for medical implants

Abstract

Surfaces of pure Ti before and after treatment with phosphoric acid and aminopropyl trimethoxysilane (APTMS) were analysed with XPS at normal emission and in angle-resolved mode. In addition, three different excitation energies with increasing analysis depth were used, namely, Mg Kα, Al Kα and Ag Lα. The use of monochromatic Ag La enabled the acquisition of both 1s, 2p and KLL peaks for Si and P. We used these peaks to identify the chemical states of Si and P via the use of the 2p-KLL and 1 s-KLL Auger parameters (AP). The Si and P AP values were in the region of silanes/silicones and phosphates respectively. The various spectral features confirmed the expected chemical states of the surfaces, except for the oxidation level of Ti in the titanium phosphate layer: results suggest the presence of a Ti(IV) phosphate instead of a Ti(III) phosphate reported in literature. Copyright © 2008 John Wiley & Sons, Ltd.