Nanopowders of YAl3(BO3)4 doped by Nd, Yb and Cr obtained by sol-gel method: Synthesis, structure and luminescence properties

Structure, morphology and luminescence properties of nanocrystalline samples of YAl3(BO3)4 (YAB) undoped and doped with neodymium, ytterbium and chromium obtained by the sol-gel method are presented. The best results of synthesis are obtained for mannitol as polymerizing agent. Single phase of nanopowder is obtained for pure YAB. Dopants destroy the compound structure; two other compounds, namely Al18B4O33 and YBO3, were revealed by X-ray investigation. Nanopowders show isometric and needles forms, the calculated size of crystallites is about 60 nm. Their optical properties are determined and results are compared to data obtained for single crystal counterparts. It is shown that the influence of rare earth ions incorporated into YBO3 phase on luminescent spectra and excited state relaxation dynamics of the nanopowders is negligibly small when the YBO3 content is of the order of several wt%. Residual impurity phases do not affect significantly spectroscopic properties of YAB nanopowders.