An explanation for the anomalous temperature broadening of zero-phonon transition corresponding to 7F0↔5D0 electronic transition in Sm2+–doped sodium borate glasses is given. The main broadening mechanism is spectral diffusion induced by thermal fluctuation of long-living soft localized modes over the whole studied temperature region 5–293K.

A modification of the tape casting method optimized for preparing either uniform or linearly structured sol–gel films is presented. It is demonstrated that molecular level homogeneous high viscosity sol–gel precursors can be used instead of slurries to prepare surface coatings by the tape casting method. Such method is especially well suited for preparing thick sol–gel films from relatively high viscosity sol precursor materials. The feasibility of the method is demonstrated using linearly structured ATO precursor films.

The homogeneous width Γh of 7F0↔5D0 transition in Sm2+ ions doped into sodium borate glass was determined at T=5–293K under P=1bar and at T=5, 80 and 120K under various P up to 8kbar. The line width Γh was obtained from spectral hole burning (SHB) and time-resolved resonant fluorescence line narrowing (FLN) experiments. It was found that at P=1bar the T-dependence of Γh changes from Γh(T)∝T2 (quadratic) for T<20K to Γh(T)∝T (linear) for T>20K. Under pressure, Γh grows slightly at all three T values studied (at 80K by 1.2%/kbar and at 120K by 1.6%/kbar in the range 0–8kbar). Possible mechanisms to explain the observed T- and P-dependences of Γh are briefly discussed.