Effect of different annealing atmospheres on the structural and luminescence properties of Ce3+-doped YAG phosphors synthesized by sol–gel method

Optical and structural properties of composites films based on Ce3+‐doped yttrium aluminium garnet nanoparticles embedded in polystyrene

“…The reduced intensity of the peaks associated with the YAG phases was justified by the reduced concentration of the filler nanoparticles in the composite. [ 21 ] Based on the Scherrer equation in the reflection of the peak (420), we were able to determine the crystallite size of the nanoparticles formed in the YAG:Ce powder and YAG:Ce‐PS composite film: [ 22 ] where β hkl is the full half width maximum (FWHM) of the pure diffraction profile in radians, k is the shape factor (0.9), λ is the wavelength of the X‐rays (0.154056 nm) and θ is the diffraction angle.…”

“…The crystal lattice strain generated by the annealing temperature was determined from the Williamson–Hall relationship. [ 22 ] For the calculation of D W‐H we used the first five most intense peaks of the Y 3 Al 5 O 12 phase. Clearly the crystallite size would be larger for the Williamson–Hall method as it includes strains induced due to vacancies, site‐disorder, etc, in the nanomaterial: where D W–H is the effective crystallite size of the Williamson– Hall model, and η is the effective strain.…”

“…For both samples there were absorption peaks at wavenumbers 690, 720 and 786 cm −1 that were ascribed to the metal–oxygen vibrations that are characteristic of M–O (M = Y, Al) stretches, confirming the existence of a YAG phase component. [ 22 ] The peaks at ~3024 and 2922 cm −1 were due to the absorption of the aromatic CH. Absorption peaks at wavenumbers 1600, 1490, 1453 and 1027 cm −1 were due to the absorption of aromatic C=C stretching vibrations.…”

“…The crystal lattice strain generated by the annealing temperature was determined from the Williamson-Hall relationship. [22] For the calculation of D W-H we used the first five most intense peaks of the Y 3 Al 5 O 12 phase. Clearly the crystallite size would be larger for the Williamson-Hall method as it includes strains induced due to vacancies, site-disorder, etc, in the nanomaterial:…”

Garnet-Type Nanophosphors for White LED Lighting

“…The sol-gel synthesis of YAG:Ce NCs involves metal alkoxides as Y, Al precursors (which can be partly replaced by metal salts, generally Y or Ce nitrates) in alcoholic or aqueous solutions, that are converted into a gel through hydrolysis and condensation reactions (∼60 • C) (Veith et al, 1999;Devi et al, 2008;Boukerika et al, 2014;Zhang et al, 2017). The resulting gels are then dried into powders and further annealed at around 1,000 • C, leading to YAG NCs with different agglomeration levels depending on temperature, duration and atmosphere used during heating treatments (Kareiva, 2011;Boukerika et al, 2016;Sundarakannan and Kottaisamy, 2016). Several conditions have been implemented to have a better control over the YAG:Ce particle size.…”