Energy transfer study between (Yb, Pr), (Yb, Sm) and (Yb, Dy) in fluorohafnate glasses

Abstract

The energy transfer mechanism among Yb and Pr, Sm or Dy in fluorohafnate glasses has been examined. The Yb 3+ ions are the donor ions and Pr 3+, Sm 3+ or Dy 3+ are the acceptor ones. Donor luminescence decay measurements are anakyzed using the kinetic models developed for direct energy transfer and excitation diffusion. For low Yb 3+ concentration (0.1 mol%) the excitation is transferred directly to the acceptors and migration of energy between the Yb 3+ ions is negligible. The results are compatible with a dipole-dipole interaction mechanism among donors and acceptors. By increasing the donor concentration, it has been possible to change the energy diffusion parameter D by over two orders of magnitude, but the limit of fast diffusion was not reached. Finally the donor-acceptor and donor-donor transfer parameters obtained from luminescence decay measurements are given and they are compared with those obtained from spectroscopic data for the donor and acceptor ions.