Developments in Ceramic Materials Research

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T. T. Basiev, V. A. Demidenko, K. V. Dykel’skii et al.
transition. Table 1 presents approximate values of energy gaps ΔEmin, ωmax and a minimal
number of phonons pmin for the samples in study.
Figure 25. Raman spectra of the La 2O 2S:Nd 3+ —1 and Gd 2O 2S:Nd 3+ —2 optical ceramics at 300 K.
Photon counts
10 2
10 1
10 0
10 -1
10 -2
10 -3
10 -4
2
4 G 7/2 level
3
T=300 K
1
1 La2O2S:Nd 3+ (1%) τ=37.5 ns
2 Gd2O2S:Nd 3+ (0.5 w%) τ=19.3ns
3 set-up response function τ=12 ns
0 100 200 300 400 500
time, ns
Figure 26. Fluorescence kinetics of the 4 G 7/2 manifold in La 2O 2S: Nd 3+ (1 wt%)—1, Gd 2O 2S:Nd 3+
(0.5 wt%)—2 at room temperature under 511 nm excitation detected at the 4 G 7/2→ 4 I 13/2 transition and
the setup response function−3, and the positions of time gates for the fluorescence spectra
measurements at the same transition.
The fluorescence decay curves of the high-lying strongly quenched 4 G7/2 level in the
Gd2O2S:Nd 3+ (0.5 wt%) and La2O2S:Nd 3+ (1 wt%) optical ceramics are measured at the
visible 4 G7/2→ 4 I13/2 transition at room (Figure 26) and liquid nitrogen temperatures (Figure