In and Cd as defect traps in titanium dioxide
Schell, J. and Lupascu, D.C. and Martins Correia, J.G. and Carbonari, A.W. and Deicher, M. and Barbosa, M.B. and Mansano, R.D. and Johnston, K. and Ribeiro, I.S., Jr. and ISOLDE collaboration
Volume: 238 Pages:
We present a study of TiO2 single crystals from the point of view of the dopant atom that simultaneously behaves as the probing element. We used gamma-gamma time dependent perturbed angular correlations working with selected tracer elements (111In/ 111Cd, 111mCd/ 111Cd) together to investigate the different behavior of Cd and In dopants, particularly their interaction with point defects in the TiO2 lattice. Results show that the hyperfine interactions observed at 111Cd from 111In or 111mCd decay are quite different. 111In/ 111Cd results show a single site fraction characterized by a quadrupole frequency with asymmetry parameter similar to those observed for the same probe nuclei in bulk TiO2 oxides. Results for 111mCd/ 111Cd reveal two site fractions, one characterized by the same hyperfine parameters to those measured in bulk TiO2 and another fraction characterized by a quadrupole frequency and asymmetry parameters with higher values, as observed in thin TiO2 films and correlated with point defects. The results are discussed emphasizing the differences for Cd and In as defect traps on TiO2. © 2016, Springer International Publishing Switzerland.