White light emission materials of self‐assembled rare earth molybdates NaRe(MoO₄)₂ micro‐particles: the controllable synthesis, growth mechanism and luminescent properties

Abstract

The tetragonally double alkaline rare earth molybdates NaRe(MoO 4 ) 2 (Re = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Er) micro-particles in aqueous solution of Re(NO 3 ) 3 and Na 2 MoO 4 were prepared hydrothermally by a facile and effective EDTA-assisted method, and investigated by XRD, SEM, FE-SEM, photoluminescence (PL) excitation and emission spectra. The results showed that the radii of Re ions, pH and the molar ratio of Re(NO 3 ) 3 /Na 2 MoO 4 in the synthesis solution play an important role in controlling sizes, morphologies and luminescent properties of the final products. And the possible formation mechanism for the bipyramid-like structure and role of EDTA were discussed in detail. The microstructure and PL property of NaY x La 1-x (MoO 4 ) 2 :10%Eu 3+ was investigated, and it showed that NaY 0.5 La 0.5 (MoO 4 ) 2 exhibited regular sphere-like morphology and emitted the stronger red emission with better color purity than other products.

New Solid Electrolyte Na9Al(MoO4)6: Structure and Na+ Ion Conductivity

“…In addition to their use in Na ion batteries, double molybdates containing both alkali and trivalent cations are attractive for many industrial applications, including solid electrolytes, ferroelectrics, photocatalysts, and optical materials (white light-emitting diodes and solid state lasers). − The Na x R y (MoO 4 ) ( x +3 y )/2 ( R = trivalent cations) molybdates found in the Na 2 MoO 4 – R 2 (MoO 4 ) 3 systems are known to exist at a wide range of x : y ratios. The vast majority of the published Na x R y (MoO 4 ) ( x +3 y )/2 ( R = trivalent cations) molybdates exhibit 1:1 x : y Na: R ratios; nevertheless, there are also compounds with Na: R compositions of 5:1, 1:5, 3:1, and 9:1. , …”

Influence of Ce ion Concentration on Fluorescence Properties of Ce:TAG‐Al2O3 Eutectic Mixed Crystals

“…The performances of fluorescent materials directly affect the white LED luminous efficiency, color coordinates, color temperature, brightness and other performances. It is very popular to combine a LED chip with phosphor to obtain white light, such as a combination of GaInN blue chip with yellow light‐emitting phosphors . Phosphor absorbs part of the blue light and then emits yellow light.…”

Single Crystals of KRE(MoO4)2, (RE‐ Ce, Pr) Obtained from Fluorides: Scheelite‐Related Structure and Luminescence

“…The structure of them is closely related to the scheelite structure with randomly or ordered distribution of metals on the MO 8 sites. Some of them represent a tetragonal structure, namely NaGd(MoO 4 ) 2 , with the space group I4 1 /a . When metals distribution is more complicated the symmetry of the framework lowers toward a monoclinic one or became a modulated one, like KEu(MoO 4 ) 2 and NaEu(MoO 4 ) 2 …”