TY - JOUR

T1 - Synthesis, structure and photoluminescent properties of Eu:Gd2O3 nanophosphor synthesized by cw CO2 laser vaporization

AU - Kostyukov, Anton I.

AU - Snytnikov, Vladimir N.

AU - Snytnikov, Vladimir N.

AU - Rakhmanova, Marianna I.

AU - Kostyukova, Nadezhda Y.

AU - Ishchenko, Arcady V.

AU - Cherepanova, Svetlana V.

AU - Krylov, Alexander S.

AU - Aleksandrovsky, Aleksandr S.

N1 - Funding Information: The TEM studies аrе conducted using the equipment of the Center of Collective Use « National Center of Catalyst Research». This work is financially supported by the Russian Foundation for Basic Research (RFBR), Project no. 19-32-60027 . Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/7

Y1 - 2021/7

N2 - Europium doped Gd2O3 sphere-like nanoparticles with dm = 9.3 ± 3.5 nm were synthesized by cw CO2 laser vaporization technique in a flowing mixture of argon and oxygen. According to XRD data, the Eu:Gd2O3 nanoparticles crystallize in the monoclinic symmetry class (C2/m space group). High-resolution luminescence spectroscopy study showed that the ultra-narrow 5D0 → 7F0 transition of Eu3+ demonstrates only two peaks corresponding to two inequivalent Cs positions of Eu3+ ion in monoclinic Gd2O3 lattice that is explained by the peculiarities of local environment of Eu3+ ion at these sites. The hypersensitive transition 5D0 → 7F2 dominates in the spectrum and is expanded to the red part of the spectrum in comparison with cubic Eu:Gd2O3 due to intense transitions terminating at higher-lying components of the crystal-field-split 7F2 state. In the luminescence spectrum, an additional weak band with the maximum at 407 nm corresponding to the electronic transitions 4f65 d1(7FJ) → 4f7(8S7/2) of Eu2+ was detected. The obtained values of chromaticity coordinates and absolute quantum yield are (0.644; 0.325) and ca. 1%, respectively. The phase transformations have been investigated using differential scanning calorimetry and thermogravimetry (50–1400 °C). After annealing in air at 700 °C, the monoclinic symmetry class of the Eu:Gd2O3 nanoparticles is preserved and the particle size increases to dm = 17.8 ± 6.1 nm. After annealing, the chromaticity coordinates (0.659; 0.334) and absolute quantum yield (ca. 4%) can be obtained using red phosphor based on monoclinic Gd2O3:Eu3+. The lifetime of the excited 5D0 state of Eu3+ in the annealed nanoparticles is longer than that in the as-synthesized nanoparticles, due to the suppression of nonradiative decay after annealing.

AB - Europium doped Gd2O3 sphere-like nanoparticles with dm = 9.3 ± 3.5 nm were synthesized by cw CO2 laser vaporization technique in a flowing mixture of argon and oxygen. According to XRD data, the Eu:Gd2O3 nanoparticles crystallize in the monoclinic symmetry class (C2/m space group). High-resolution luminescence spectroscopy study showed that the ultra-narrow 5D0 → 7F0 transition of Eu3+ demonstrates only two peaks corresponding to two inequivalent Cs positions of Eu3+ ion in monoclinic Gd2O3 lattice that is explained by the peculiarities of local environment of Eu3+ ion at these sites. The hypersensitive transition 5D0 → 7F2 dominates in the spectrum and is expanded to the red part of the spectrum in comparison with cubic Eu:Gd2O3 due to intense transitions terminating at higher-lying components of the crystal-field-split 7F2 state. In the luminescence spectrum, an additional weak band with the maximum at 407 nm corresponding to the electronic transitions 4f65 d1(7FJ) → 4f7(8S7/2) of Eu2+ was detected. The obtained values of chromaticity coordinates and absolute quantum yield are (0.644; 0.325) and ca. 1%, respectively. The phase transformations have been investigated using differential scanning calorimetry and thermogravimetry (50–1400 °C). After annealing in air at 700 °C, the monoclinic symmetry class of the Eu:Gd2O3 nanoparticles is preserved and the particle size increases to dm = 17.8 ± 6.1 nm. After annealing, the chromaticity coordinates (0.659; 0.334) and absolute quantum yield (ca. 4%) can be obtained using red phosphor based on monoclinic Gd2O3:Eu3+. The lifetime of the excited 5D0 state of Eu3+ in the annealed nanoparticles is longer than that in the as-synthesized nanoparticles, due to the suppression of nonradiative decay after annealing.

KW - Eu ions

KW - Laser vaporization

KW - Monoclinic GdO

KW - Nanophosphors

KW - Photoluminescence

UR - http://www.scopus.com/inward/record.url?scp=85102474009&partnerID=8YFLogxK

U2 - 10.1016/j.jlumin.2021.118050

DO - 10.1016/j.jlumin.2021.118050

M3 - Article

AN - SCOPUS:85102474009

VL - 235

JO - Journal of Luminescence

JF - Journal of Luminescence

SN - 0022-2313

M1 - 118050

ER -