Pleomorphic structural imperfections caused by pulsed Bi-implantation in the bulk and thin-film morphologies of TiO 2

Abstract

The results of combined experimental and theoretical study of pleomorphic substitutional and clustering effects in Bi-doped TiO 2 hosts (bulk and thin-film morphologies) are presented. Bi-doping of the bulk and thin-film titanium dioxide was made with help of pulsed ion-implantation (E Bi + = 30 keV, D = 1 × 10 17 cm -2 ) without posterior tempering. The X-ray photoelectron spectroscopy (XPS) qualification (core-levels and valence bands) and Density-Functional Theory (DFT) calculations were employed in order to study the electronic structure of Bi-ion implanted TiO 2 samples. According to XPS data obtained and DFT calculations, the Bi → Ti cation substitution occurs in Bi-implanted bulk TiO 2 , whereas in the thin-film morphology of TiO 2 :Bi the Bi-atoms have metal-like clusters segregation tendency. Based on the combined XPS and DFT considerations the possible reasons and mechanism for the observed effects are discussed. It is believed that established peculiarities of bismuth embedding into employed TiO 2 hosts are mostly the sequence of pleomorphic origin for the formed "bismuth-oxygen" chemical bonding. © 2016 Elsevier B.V. All rights reserved.