Comparison of the spectra and dynamics of Er(sup 3+):Y(sub 2-x)Sc(sub x)O(sub 3) (x = 0,1,2).

摘要

We have studied the spectra and lifetimes of Er(sup 3+) in the isostructural series, Y(sub 2)O(sub 3), YScO(sub 3), and Sc(sub 2)O(sub 3). Addition of Sc(sup 3+) to Er(sup 3+):Y(sub 2)O(sub 3) shifted the energy level positions, changed the inhomogeneous broadening and shortened the fluorescence lifetimes for Er(sup 3+) in the C(sub 2) site. Going from Er(sup 3+):Y(sub 2)O(sub 3) to Er(sup 3+):Sc(sub 2)O(sub 3) increased the barycenter of the four lowest J-multiplets, decreased the barycenter of the (sup 4)F(sub 9/2) and higher multiplets, and increased the crystal-field splitting within each J-multiplet. The inhomogeneous linewidths in the Er(sup 3+):YScO(sub 3) spectra were much larger than in Er(sup 3+):Y(sub 2)O(sub 3) or Er(sup 3+):Sc(sub 2)O(sub 3) due to random substitutional disorder in the mixed system. The random disorder in Er(sup 3+):YScO(sub 3) removed the inversion symmetry of the C(sub 3i) lattice site and allowed observation of transitions from Er(sup 3+) ions in this site. All fluorescence lifetimes decreased with addition of Sc(sup 3+) indicating an increase in the nonradiative relaxation. 13 refs., 3 figs., 3 tabs.