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Gd-incorporation and luminescence properties in sol–gel silica glasses

2008; Elsevier BV; Volume: 354; Issue: 32 Linguagem: Inglês

10.1016/j.jnoncrysol.2008.05.027

1873-4812

Daniela Di Martino, N. Chiodini, Mauro Fasoli, Federico Moretti, A. Vedda, A. Baraldi, E. Buffagni, R. Capelletti, Margherita Mazzera, M. Nikl, Giuliano Angella, Carlo B. Azzoni,

Radiation Detection and Scintillator Technologies

A thorough study was performed on Gd-doped sol–gel silica glasses, in the concentration range 0–8 mol% Gd. The analyses were carried out as a function of Gd content, before and after a post-densification thermal treatment. Different results concerning optical, vibrational, magnetic, and structural features were gathered in correlated experiments. The presence of Gd-rich nanoclusters was revealed. The size of nanoclusters increases by increasing the dopant concentration and by performing a rapid thermal treatment (RTT) at 1800 °C in air, which causes also a remarkable intensity increase of the 6P7/2 → 8S7/2 radioluminescence transition of Gd3+. Nanoclusters are amorphous, possibly close to a Gd2SiO5 stoichiometry as suggested by fast Fourier transform infrared spectroscopy (FTIR). FTIR studies revealed also the presence of Gd-dimers interacting with OH− groups. Moreover, the presence of isolated Gd3+ ions was detected by electron paramagnetic resonance investigations. Based on the results obtained with different techniques, the Gd-incorporation in silica glass host and the resulting optical properties are discussed.