Luminescence Properties of Nanocrystalline BaF2 Synthesized by Laser Ablation Technique and Pulsed Electron Beam Evaporation Method.

In this paper, studies of the effect of morphology and particle size of BaF₂ nanopowders obtained by laser ablation method and by pulsed electron beam evaporation method on luminescent properties are presented. SEM-images of the morphology of all samples are presented. In the X-ray excited luminescence spectra of nanopowders, a redistribution of the relative intensity is observed between the self-trapped exciton and core-valence bands. This may be due to a smaller influence of particle size on the mechanism of formation of the cross-luminescence band. The change in the shape of the self-trapped exciton spectrum is also observed for nanosized samples. This effect can be associated with the possibility of the formation of certain STE configurations inside a nanoscale crystal due to the different relative position of the F and H centers parts with respect to each other. [ABSTRACT FROM AUTHOR]