A benign approach for novel synthesis of Eu3+ doped MgNb2O6: Its photoluminescence and photocatalytic studies

Luminescent and thermal properties of novel orange–red emitting MgNb2O6:Sm3+ phosphors for displays, photo catalytic and sensor applications

“…The microstructures of the samples confirm the consistent distribution of irregular particles, forms agglomeration with average particle size to be around 25 nm [ Fig. 3 confirms the Sm doping and purity of the sample [18]. SEM was predominantly utilized to contemplate the composition, porous, voids, agglomerated morphologies of the powders prepared via combustion process and the same was observed at different magnifications ( Fig.…”

“…The symmetric and asymmetric stretching vibrations of samples were found at 1462 cm −1 indicating metal oxygen [Mg-O, Sm-O, Nb-O] vibrations. Also, the presence of peaks in the range 550-850 cm −1 was indicating to the coordination between metal ions [18].…”

“…The emission at 608 nm was hyper sensitive in nature when dopant ions occupies CS site results in characteristic orange red emission which was partly magnetic and partly electric dipole transition with shoulder peaks may be due to (2 J + 1) splitting, the transition at 656 nm was due to purely electric dipole (ED) sensitive to the crystal field [36,37], no emission peak positions shifted while doping concentrations were relatively varied, suggesting that the nature of Sm 3+ activators remained unchanged, whereas the intensity reaches maximum at 5 mol% and falls afterwards (inset of Fig. 9) due to concentration quenching [18].…”

“…The QE for the MNO:Sm 3+ (5 mol%) nanophosphor was estimated to be ~ 68% by integrated emission counts from the 500-750 nm. The J-O parameters Ω λ were estimated in detail [44][45][46] to study the site symmetry and luminescence behavior of the Sm 3+ ions in MNO host crystal to understand site symmetry and luminescence behavior using emission data, the adopted procedure is similar to our earlier work [18]. Spontaneous emission probability (A R ), the experimental intensity of 4 G 5/2 to 6 H 7/2 transitions Ω λ (λ = 2, 4 and 6), Total radiative rate (A T ), Non-radiative rates (A NR ), luminescence quantum efficiency ( ), fluorescence branching ratio (β), radiative lifetime ( rad ) were estimated.…”

“…Magnesium niobate doped with Sm 3+ (1-11 mol%) nanophosphors were synthesized by solution combustion route [15]. The precursors used in the synthesis are Niobium pentoxide (Nb 2 O 5 ) (99.95%, Sisco research laboratories (SLR)), Ammonium nitrate (NH4(NO 3 ) 2 ), Magnesium nitrate (Mg(NO 3 ) 2 (99%, SLR), Samarium oxide (Sm 2 O 3 ) (99.99% Sigma Aldrich Ltd) and Oxalyl dihydrazide (ODH-C 2 H 6 N 4 O 2 ) (lab made) as a fuel [18]. Initially the Sm 2 O 3 is converted into Sm(NO 3 ) 2 by using a small amount of 1:1 HNO 3 and subjected to heating followed by drying.…”