Sujita Karki - Academia.edu (original) (raw)

Papers by Sujita Karki

Research paper thumbnail of Physical, optical and luminescence properties of B 2 O 3 -SiO 2 -Y 2 O 3 -CaO glasses with Sm 3+ ions for visible laser applications

Journal of Luminescence, 2018

Silicoborate glasses with composition of (BSYCaSm:(55-x)B 2 O 3 + 10SiO 2 +25Y 2 O 3 +10CaO + xSm... more Silicoborate glasses with composition of (BSYCaSm:(55-x)B 2 O 3 + 10SiO 2 +25Y 2 O 3 +10CaO + xSm 2 O 3), (where, x= 0.05, 0.10, 0.20, 0.25, 0.30, 0.40, 0.50, mol%) have been synthesized by using the well-known melt quenching technique. The present work deals with physical, optical, photoluminescence, X-ray luminescence and decay time studies of silicoborate glasses. Judd-Ofelt (JO) intensity parameters (Ω 2, Ω 4 and Ω 6) and radiative properties for the important luminescent level of Sm 3+ ions were derived by using the absorption spectrum of 0.3 mol% Sm 2 O 3 doped glass. The luminescence spectra in the visible region was obtained due to 4 G 5/2 → 6 H J (5/2, 7/2, 9/2 and 11/2) transition of Sm 3+ ion under 401 nm excitation. The decay profile for the 4 G 5/2 level of Sm 3+ ions was analyzed and found that for lower concentration (≤ 0.20 mol%) it is single exponential in nature whereas for higher concentration (≥ 0.25mol%), it turns in to nonexponential due to the transfer of energy between donor (excited state Sm 3+ ion) and acceptor (ground state Sm 3+ ion).As the concentration of Sm 3+ ions increases the decay time of 4 G 5/2 state decreases. The well-known Inokuti-Hirayama (IH) model was used for fitting the nonexponential decay curves where S = 6 indicates that energy transfer process is of dipole-dipole type. Hence, in the present work, intense transition of 4 G 5/2 → 6 H 7/2 (601 nm) is found to be 2 suitable for reddish-orange laser emission. CIE chromaticity diagram has been performed for verifying the results of fluorescence in visible laser applications at 601 nm.

Research paper thumbnail of Physical, optical and luminescence properties of B 2 O 3 -SiO 2 -Y 2 O 3 -CaO glasses with Sm 3+ ions for visible laser applications

Journal of Luminescence, 2018

Silicoborate glasses with composition of (BSYCaSm:(55-x)B 2 O 3 + 10SiO 2 +25Y 2 O 3 +10CaO + xSm... more Silicoborate glasses with composition of (BSYCaSm:(55-x)B 2 O 3 + 10SiO 2 +25Y 2 O 3 +10CaO + xSm 2 O 3), (where, x= 0.05, 0.10, 0.20, 0.25, 0.30, 0.40, 0.50, mol%) have been synthesized by using the well-known melt quenching technique. The present work deals with physical, optical, photoluminescence, X-ray luminescence and decay time studies of silicoborate glasses. Judd-Ofelt (JO) intensity parameters (Ω 2, Ω 4 and Ω 6) and radiative properties for the important luminescent level of Sm 3+ ions were derived by using the absorption spectrum of 0.3 mol% Sm 2 O 3 doped glass. The luminescence spectra in the visible region was obtained due to 4 G 5/2 → 6 H J (5/2, 7/2, 9/2 and 11/2) transition of Sm 3+ ion under 401 nm excitation. The decay profile for the 4 G 5/2 level of Sm 3+ ions was analyzed and found that for lower concentration (≤ 0.20 mol%) it is single exponential in nature whereas for higher concentration (≥ 0.25mol%), it turns in to nonexponential due to the transfer of energy between donor (excited state Sm 3+ ion) and acceptor (ground state Sm 3+ ion).As the concentration of Sm 3+ ions increases the decay time of 4 G 5/2 state decreases. The well-known Inokuti-Hirayama (IH) model was used for fitting the nonexponential decay curves where S = 6 indicates that energy transfer process is of dipole-dipole type. Hence, in the present work, intense transition of 4 G 5/2 → 6 H 7/2 (601 nm) is found to be 2 suitable for reddish-orange laser emission. CIE chromaticity diagram has been performed for verifying the results of fluorescence in visible laser applications at 601 nm.