Local structure of Sn implanted in thin SiO2 films
Local structure of Sn implanted in thin SiO2 films
Spiga, S.; Montovan, R.; Franciulli, M.; Ferretti, N.; Boscherini, F.; Schmidt, B.; Grötzschel, R.; Mücklich, A.
Abstract
The formation and the structural properties of Sn nanocrystals produced by ion implantation in thin SiO2 films was investigated by 119Sn conversion electron Moessbauer spectroscopy (CEMS), x-ray absorption spectroscopy (XAS), and transmission electron microscopy (TEM). Sn ion implantation was performed at 80 keV with a fluence of 1x1016 cm2, positioning the peak of the implantation profile in the middle of the SiO2. The annealing treatments were performed in the temperature range 8001100 °C by rapid thermal processing. CEMS and XAS provided unique information on the local atomic and electronic environment of Sn in SiO2 allowing a detailed investigation of the effect of different annealing conditions. In the as-implanted state all Sn ions are oxidized (with both Sn2+ and Sn4+ oxidation states present), while annealing induces the formation of beta-Sn nanoclusters. TEM showed that cluster sizes are in the range 717 nm. For clusters with average diameter ,10 nm, XAS detected a reduction in coordination number and interatomic distances. Both XAS and CEMS indicate an increase in the static disorder in the metallic clusters. The investigated annealing treatments do not lead to a complete precipitation of Sn atoms in the metallic phase, leaving a fraction of them oxidized.
Keywords: Sn nanocluster; ion implantation; CEMS; XAS; TEM; RBS
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Physical Review B 68 (2003) 205419-1 - 205419-10
DOI: 10.1103/PhysRevB.68.205419
Cited 24 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-5931