Vol. 40, Issue 2, pp. 375-382 (2010)

Abstract

The 50GeO₂–(50–x–y)PbO–yPbF₂–xLnF₃ glass single doped with Pr³⁺ and Tb³⁺ ions was studied. The composition of the material was modified by varying the content of both PbF₂ (y = 5, 10, 15 mol%) and LnF₃ (x = 0.2 and 2 mol%). The differential thermal analysis (DTA) of as-melted samples was used to determine thermal characteristics. Optical techniques and kinetics measurements were used to monitor the effect of thermal treatment on spectroscopic properties and dynamics of luminescent states of optically-active ions in amorphous and two-phase systems. It was found that non-exponential decays of praseodymium luminescence in as-melted material become exponential or nearly exponential with corresponding longer lifetimes in thermally-treated samples. This effect was not so strong in the Tb³⁺-doped glass. The influence of the PbF₂ content on luminescence dynamics was studied for samples doped with 2 mol% of Pr³⁺. It was observed that the increase of PbF₂ content leads to lengthening of luminescence lifetime, e.g., the ¹D₂ lifetime increases from 4.1 to 45 μs in 5 and 15 mol% of PbF₂ as-melted samples, respectively.