The study of the optical properties of a LiLuF(4) crystal doped with Tm(3+) yielded the discovery of a strong temperature dependence of the Tm-Tm diffusion coefficient. Spectroscopic characteristics have been investigated as a function of the sample temperature, with particular regard to the luminescence decay following pulsed excitation. An appreciable excitation of the lifetime of the (3)F(4) manifold is observed over the temperature range 8.9-298 K. The Judd-Ofelt calculations point out a radiative lifetime considerably longer than the experimental one. These facts suggest a theoretical interpretation based on the presence of impurities that quench the manifold and on a temperature-dependent energy migration between Tm(3+) ions. A one-parameter best fit of the experimental measurements strongly confirms this hypothesis. Weak OH(-) ion concentration is detected by means of IR and UV spectra, thus supporting the theoretical interpretation. (C) 2001 Elsevier Science Ltd. All rights reserved.
Temperature dependence of impurity quenched luminescence in Tm3+: LiLuF4
TONCELLI, ALESSANDRA;TONELLI, MAURO
2002-01-01
Abstract
The study of the optical properties of a LiLuF(4) crystal doped with Tm(3+) yielded the discovery of a strong temperature dependence of the Tm-Tm diffusion coefficient. Spectroscopic characteristics have been investigated as a function of the sample temperature, with particular regard to the luminescence decay following pulsed excitation. An appreciable excitation of the lifetime of the (3)F(4) manifold is observed over the temperature range 8.9-298 K. The Judd-Ofelt calculations point out a radiative lifetime considerably longer than the experimental one. These facts suggest a theoretical interpretation based on the presence of impurities that quench the manifold and on a temperature-dependent energy migration between Tm(3+) ions. A one-parameter best fit of the experimental measurements strongly confirms this hypothesis. Weak OH(-) ion concentration is detected by means of IR and UV spectra, thus supporting the theoretical interpretation. (C) 2001 Elsevier Science Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
