Lattice location and perturbed angular correlation studies of implanted Ag in SrTiO3
Marques, A. C × Wahl, Ulrich Correia, J. G Rita, E Soares, J. C #
Nuclear Instruments & Methods in Physics Research B vol:249 pages:882-885
Lattice site location and local environment characterization of implanted Ag-111 in SrTiO3 by means of the emission channeling (EC) and gamma-gamma perturbed angular correlation (PAC) techniques are reported. The angular distribution of beta(-) particles emitted from the Ag-111 decay was monitored with a position-sensitive detector as a function of annealing temperature up to 900 degrees C. In the as-implanted state Ag occupies several lattice sites in SrTiO3, Upon annealing, near-Sr and near-Ti occupancies increased to 64% and 18%, while an octahedral interstitial fraction vanished. Ag atoms on near-Sr and near-Ti sites are still displaced by similar to 0.2 angstrom from ideal cubic positions. Subsequent PAC measurements confirmed that similar to 20% of Ag-111 atoms are in specific sites of non-cubic environment, characterized by a unique electrical-field-gradient (EFG), while similar to 80% were subject to a wide EFG distribution. (c) 2006 Elsevier B.V. All rights reserved.