Yamaga, Mitsuo and Uno, Hideaki and Tsuda, Shin-ichiro and Wells, Jon-Paul R. and Han, Thomas P. J. (2012) Resonant energy transfer and cross relaxation between Sm3+ ions in LiYF4 crystals. Journal of Luminescence, 132 (6). pp. 1608-1617. ISSN 0022-2313Full text not available in this repository. (Request a copy from the Strathclyde author)
Luminescence decay curves of Sm3+ ions in LiVF4 crystals doped with 1.5 and 10 mol% Sm3+ are multi-exponential, whereas that in a LiYF4 crystal doped with 0.1 mol% Sm3+ is well approximated by a single exponential function with a decay time of 4.8 ms. The average luminescence decay times decrease from 4.8 to 0.60 ms with the increasing Sm3+ concentrations between 1 and 10 mol%. The decay curves for all crystals are found to be almost independent of the temperature between 15 and 300 K. The decrease of the decay times for the higher Sm3+ concentrations indicates energy transfer between two Sm3+ ions. Taking the crystal structure of LiYF4 into account, it is deduced that a single-step energy transfer process for the 1 and 5 mol% Sm3+ concentrations occurs from a Sm3+ ion at the origin of (0 0 0) to one of the Sm3+ ions substituting for the first nearest neighbor Y3+ sites and beyond within a sphere with an approximate radius of less than 0.7 nm. On the other hand, a multi-step energy transfer process dominates for the highest concentration (10 mol%) because the calculated average distance between two Sm3+ ions in the 10 mol% Sm3+ sample is comparable with the migration length of the single-step energy transfer process estimated from the 1 and 5 mol% Sm3+ samples.
|Keywords:||samarium, LiYF4, luminescence, energy transfer, cross relaxation, Physics, Biochemistry, Biophysics, Atomic and Molecular Physics, and Optics, Chemistry(all), Condensed Matter Physics|
|Subjects:||Science > Physics|
|Department:||Faculty of Science > Physics|
|Depositing user:||Pure Administrator|
|Date Deposited:||10 May 2012 13:29|
|Last modified:||16 Sep 2016 02:27|