High-pressure fluorescence study of Sm3+-doped borate and fluoroborate glasses -: art. no. 093523

Fluorescence spectra and decay properties of the (4)G(5/2) level of the Sm3+ ions have been measured in two glass systems of lithium borate and lithium fluoroborate glasses as a function of pressure up to 27.2 and 25.9 GPa, respectively, at room temperature. With an increase in pressure continuous redshifts of the (4)G(5/2)-> H-6(J) (J=9/2,7/2, and 5/2) multiplet transitions as well as progressive increases in the magnitude of the splittings for these transitions are observed. Decay curves in both the systems exhibit perfect single exponential behavior at ambient pressure and become nonexponential at higher pressures accompanied by a moderate decrease in lifetimes. The nonexponential decay curves fit well to the Inokuti-Hirayama [M. Inokuti and F. Hirayama, J. Chem. Phys. 43, 1978 (1965)] model for S=6, indicating that the interaction for cross relaxation is of dipole-dipole type. The decrease in lifetime of the (4)G(5/2) level in both the systems with pressure is explained as resulting from the increase in the crystal-field strength felt by the Sm3+ ions due to volume reduction accompanied by a simultaneous increase in the electronic transition probabilities. (C) 2005 American Institute of Physics.