Study of the atomic dynamics of nanoclusters Y₂SiO₅:Pr³⁺ by the confocal fluorescent microscopy

The system under consideration consists of a Pr³⁺ ion placed into a nanodimensional Y₂SiO₅ crystal (∼20 nm), which rests on a glass substrate. The spectrum and attenuation of the fluorescence of the Pr³⁺ ion have been studied by the method of confocal fluorescent microscopy. The rapid electron relaxation in J-multiplets of rare earth impurity ions split by the crystal field (for a usual bulk crystal τ∼10^–9–10^–12 sec) is shown to be suppressed in the nanodimensional crystal of Y₂SiO₅:Pr³⁺. For the excited Stark components of ¹D₂ multiplet, the electron relaxation appears to be more than 10⁴ times suppressed, while an average splitting of the ¹D₂ multiplet by the crystal field of ligands is 200 cm^–1. The observed phenomena strongly depends on the interaction of the Y₂SiO₅:Pr³⁺ cluster with the substrate and the surrounding (‘matrix’). Experimental results and theoretical calculations show the noticeble changes in the structure of vibrational spectrum and the density of vibrational states of the nanodimensional Y₂SiO₅:Pr³⁺ crystal. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)