| Abstract [eng] |
Synthesis and Characterization of Rare Earth Doped GdB5O9 GdB5O9 doped with Eu3+, Sm3+ and Pr3+ ions were prepared by sol-gel synthesis method. The concentration of dopants in compounds was 1,0 %, 2,5 %, 5 %, 10 %, 25 %, 50 %, 75 % and 100 %. XRD of synthesized materials showed that all the investigated compounds are of single phase. SEM microscopy was used to determine the particle size and morphology, which photos gives information that all samples particle are similar of each other, small and have different size. Using Edinburgh Instruments FLS980 spectrometer reflection, excitation and emission spectra were recorded in UV/VIS range. GdB5O9: Eu3+ phosphors showed emission in red region under ultraviolet excitation (λex = 394,5 nm), GdB5O9: Sm3+ phosphors exhibit emission in orange region under excitation λex = 400 nm, GdB5O9: Pr3+ phosphors showed emission in red-orange region under λex = 445 nm excitation. Emission measurements were investigated in temperature range from 77 to 500 K, when excitation for Eu3+ doped samples was λex = 394,5 nm, for Sm3+ samples was λex = 400 nm. Temperature impact on emission intensity results showed that emission intensity decreases with the increasing temperature. Moreover, was calculated TQ1/2 value for GdB5O9 doped with lanthanides, which for Eu3+ doped samples is from 526 K ± 29 K to 457 K ± 14 K and for Sm3+ doped samples is 538 K ± 29 K. The results obtained shows that these compounds are resistant to high temperatures. In temperature range from 77 to 500 K, temperature dependent lifetime measurements of luminescence decay revealed that temperature had significant impact on decay time. |
