Crystal structure and luminescence of the orthoborate Ln(1-x)BO(3): Eu-x Ln=Y,Gd

LnBO(3):Eu(Ln=Y,Gd)orthoborates were prepared by solid state reaction and sol-gel technique. Nephelauxetic effect was observed in the F-7(0) --> D-5(0) transition of Eu3+ in pseudo-vaterite type YBO3 when the excitation spectra were carried out at different temperatures. according to the luminescence of YBO3:Eu at low temperatures and the effect of different temperatures on the luminescence, the site symmetries of Ln(3+) in YBO3 were revised to be a D-3 and a similar Ca. Different luminescent intensities and quenching concentrations were found for the sol-gel samples and corresponding solid-state-synthesized ones. The effect of defects or dislocations was taken into account to explain these phenomena. The luminescence of annealed samples and the Raman spectra of them suggested the presence of Eu3+ clusters in the sol-gel crystalline YBO3:Eu.