XPS investigation of atomic environment changes on surface of B2O3-Bi2O3 glasses

Melt derived glasses of (1-x)B2O3 center dot xBi(2)O(3) system with 0.1 <= x <= 0.875 were investigated by X-ray photoelectron spectroscopy (XPS) in order to evidence the structural changes that occur at the surface of bismuth borate glasses as Bi/B ratio increases from 1:9 to 7:1. The high resolution)(PS spectra of O 1s, Bi 4f and B 1s photoelectrons emphasizes consistent changes in the vicinity of oxygen, and small changes around bismuth and boron atoms by increasing of Bi2O3 content. The deconvolution of O 1s spectra was used to investigate the Bi/B ratio effect on the number of bridging and non-bridging oxygens and the results obtained were discussed considering four components occurring from oxygen atoms implied in B - O - B, B - O - Bi, Bi - O - Bi and B - O - /Bi - O - bonds. From the deconvolution of Bi 4f high resolution spectra, four components related to Bi-0 and bismuth atoms connected in bonds of Bi - O - Bi, B - O - Bi and Bi - O - types were identified. It was concluded that boron and bismuth play a network former role in the entire compositional range. (C) 2013 Elsevier B.V. All rights reserved.