Vibrational modes of OH, as stretching, bending, combination, and overtones, were monitored by means of FTIR spectroscopy in Ce3 - and Gd3 -doped silicate glasses, prepared by means of the sol-gel technique, submitted to different thermal treatments, and aimed to applications as scintillators. The dopant concentration was varied in a wide range (10 -3 -8% m.f.) and co-doped samples were also investigated. In this framework, the effects of OH and of rare-earth (RE) clustering, i.e. two possible non-radiative decay channels, on the IR spectra in the 500-14 000 cm(-1) were examined. OH was detected as belonging either to water and to silanol in samples densified at 450 and 750 degreesC, while in those treated at 1050 degreesC only Si-OH groups were present in a concentration of the order of 1% m.f., nearly regardless of the RE amount. An absorption peaking at 4250 cm(-1) was identified as related to an OH combination mode (bending???) perturbed by a Gd cluster on the basis of its amplitude dependence on the Gd concentration and rapid thermal treatment.
Baraldi, A., Capelletti, R., Chiodini, N., Oppici, D., Scotti, R., Vedda, A. (2002). Vibrational spectroscopy of OH-defects in sol-gel Ce3 and Gd3+doped silicate glasses. RADIATION EFFECTS AND DEFECTS IN SOLIDS, 157(6-12), 1139-1143 [10.1080/10420150215814].
Vibrational spectroscopy of OH-defects in sol-gel Ce3 and Gd3+doped silicate glasses
CHIODINI, NORBERTO;SCOTTI, ROBERTO;VEDDA, ANNA GRAZIELLA
2002
Abstract
Vibrational modes of OH, as stretching, bending, combination, and overtones, were monitored by means of FTIR spectroscopy in Ce3 - and Gd3 -doped silicate glasses, prepared by means of the sol-gel technique, submitted to different thermal treatments, and aimed to applications as scintillators. The dopant concentration was varied in a wide range (10 -3 -8% m.f.) and co-doped samples were also investigated. In this framework, the effects of OH and of rare-earth (RE) clustering, i.e. two possible non-radiative decay channels, on the IR spectra in the 500-14 000 cm(-1) were examined. OH was detected as belonging either to water and to silanol in samples densified at 450 and 750 degreesC, while in those treated at 1050 degreesC only Si-OH groups were present in a concentration of the order of 1% m.f., nearly regardless of the RE amount. An absorption peaking at 4250 cm(-1) was identified as related to an OH combination mode (bending???) perturbed by a Gd cluster on the basis of its amplitude dependence on the Gd concentration and rapid thermal treatment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.