Investigation of phase formation dependency of photoluminescence properties of Eu3+ in Mg4Al2O7:Eu3+,Dy3+ and Ca4Al2O7:Eu3+,Dy3+ red-emitting phosphors

Abstract

Rare earth-doped Mg were synthesized by the solid-state reaction method at 1,400°C. The phosphors were characterized by X-ray powder diffraction, photoluminescence, thermogravimetry and differential thermal analysis and scanning electron microscopy. X-ray powder diffraction studies show that the Mg 4 Al 2 O 7 :Eu 3? ,Dy 3? phosphor was crystallized in the triclinic crystal system but that Ca 4 Al 2 O 7 : Eu 3? ,Dy 3? was not. The phosphors show the characteristic broad band phosphorescence of Eu 3? . This broad band phosphorescence has red emission bands in the range of 550-700 nm corresponding to 5 D 0 ? 7 F j (j: 1, 2, 3,) transitions of Eu 3? .

Sol–gel synthesis and luminescence property of Sr4Al2O7:Re3+,R+ (Re = Eu and Dy; R = Li, Na and K) phosphors for white LEDs

“…This is because heating phosphors at high temperatures effectively reduces the impurity phase that inhibits the luminescence intensity. High temperatures also favor the doping of Eu 3+ ions into the Sr 4 Al 2 O 7 lattice . High crystallization has an important role in improving the luminescent efficiency, as shown by the XRD result.…”

The effect of Ba/Mg impurities on the phase formation and photoluminescence properties of (Sr3−xMx)Al2O6:Eu3+,Ho3+ (M = Ba, Mg) phosphors

“…Intensity/a.u. [1,[10][11][12][13]. The major excitation peaks of the samples, which were concentrated in the range of 270-285 nm, were associated with the charge-transfer state (CTS) band which again proved that the typical Eu 3?…”

“…In stoichiometric combinations of SrO-Al 2 O 3 , such as SrAl 2 O 4 , SrAl 4 O 7 , Sr 4 A l4 O 25 , Sr 3 Al 2 O 6 and SrAl 12 O 19 , the compounds were generally prepared by the solid-state reaction method which includes the mechanical mixing of high purity and small particle sized raw materials (SrCO 3 and Al 2 O 3 ), which is necessary to prevent compositional inhomogeneities [1][2][3][4].…”

Synthesis, structure, and thermal stability of new scheelite-type Pb1−3x□xPr2x(MoO4)1−3x(WO4)3x ceramic materials

“…Lead molybdate was prepared by heating PbO with MoO 3 (both with the purity 99.95 %, Alfa Aesar) mixed in an equimolar ratio, and in the following thermal conditions: 550°C (6 h), 600°C (6 h), 700°C (6 h), 800°C (12 h), 900°C (12 h), and 950°C (12 h). Praseodymium tungstate was obtained using a solid-state reaction method [37][38][39][40][41][42][43][44][45] and Pr 6 O 11 with WO 3 (both with the purity 99.95 %, Alfa Aesar) mixed in the 1:9 molar ratio according to the procedure used by us in a synthesis of other rare-earth tungstates, and under thermal conditions reported earlier [25][26][27][28][37][38][39]. Mixtures of starting reactants with Pr 2 (WO 4 ) 3 content changing from 0.50 to 50.00 mol% were homogenized in an agate mortar.…”