Abstract

CALDINO, U et al. Energy transfer in Sr_0.6Ba_0.4Nb₂O₆ through its ferroelectric phase transition. Rev. mex. fis. [online]. 2008, vol.54, suppl.2, pp.39-43. ISSN 0035-001X.

Resonant Nd³⁺ Yb³⁺ energy-transfer in the Nd³⁺ and Yb³⁺ co-doped Sr_0.6Ba_0.4(NbO₃)₂ (SBN) crystal is investigated by using pulsed and steady state laser spectroscopy. Spectroscopic data revealed that the energy transfer occurs via a non-radiative process. The efficiency of this energy transfer was estimated from spectral data in around 35%. Back energy transfer is not observed at the 295-415 K temperature range. A marked reduction in the luminescence intensity of Yb³⁺ ions directly excited into their ²F₇/₂ ²F₅/₂ transition, taking place at around 345 K, is due to the ferro to paraelectric phase transition in SBN. This thermal behavior, which is not clearly manifested when Yb³⁺ ions are excited via Nd³⁺ ions, has been explained in terms of structural changes taking place around the Yb³⁺ ions when the crystal becomes non-polar.

Keywords : Energy transfer efficiency; luminescence; spectroscopy; SBN; Nd³⁺; Yb³⁺; phase transition.

        · abstract in Spanish     · text in English     · English ( pdf )