Influence of Bi3+ ion on structural, optical, dielectric and magnetic properties of Eu3+ doped LaVO4 phosphor

Photochromic and fluorescent ink using photoluminescent strontium aluminate pigment and screen printing towards anticounterfeiting documents

“…The excitation peaks at 235 and 274 nm were assigned to Eu(II), while the excitation peak at 378 nm was assigned to Dy(III). [9,37,[61][62][63][64] Similarly, three fluorescence peaks appeared at 416, 418, and 436 nm, respectively. The emission peaks at 416 and 418 nm are assigned to Eu(II), while the emission peak at 436 nm is assigned to Dy(III).…”

“…The emission peaks at 416 and 418 nm are assigned to Eu(II), while the emission peak at 436 nm is assigned to Dy(III). [9,37,[61][62][63][64] The screen-printed paper documents demonstrated a green-yellow emission that was detected by fluorescence microscope images under UV light (Figure 5). Both emission and excitation spectra of europium-doped strontium aluminium oxide arose from 4f 6 5D 1 $4f 7 transitions of europium (II).…”

Structural, Optical, Luminescence, and Electrical Properties of Eu/Li- and Eu/Na-Codoped Magnesium Bismuth Niobate Pyrochlores

“…Bismuth-based pyrochlores attract attention due to their dielectric properties, − mixed electronic–ionic conductivity, , photoluminescence properties, − and photocatalytic activity. − These properties proceed with both structural features ( A 2 B 2 O 6 O′) and complex tiered electron structures caused by the 6s 2 lone pair of Bi 3+ . The polarizability created by Bi 3+ , as well as the dopant atom distribution in the bismuth sublattice ( A 2 O′), predetermines the dielectric properties of the ceramics mainly. ,,− In the high-temperature region ( T ≥ 100–200 °C), mixed electronic–ionic conductivity is caused by the structural behavior of the host. − , In the pyrochlores, Bi 3+ promotes high electron mobility due to the cooperative action of the 6s and 6p orbitals, influencing the band structure, and provides the stereochemical activity and, as a result, photocatalytic properties. , In luminescent materials, Bi 3+ usually acts as a sensitizer ion, which changes the local crystal structure and transfers its excitation energy to the rare-earth (RE) ion in the matrix, efficiently increasing the photoluminescence intensity. , However, according to the data for the Bi 2– x Eu x Ti 2 O 7 and Bi 1.5– x M x Eu 0.5 Ti 2 O 7 ( M = Gd and Y) pyrochlore thin films, the maximum photoluminescence efficiency (PLE) is predetermined by the host band gap energy mainly. , In our previous work, the weak influence of Mg 2+ substitution in the host on luminescence properties for the Bi 1.6 Ho x Ti 2 O 7−δ and Bi 1.6 Mg 0.1 Ho x Ti 2 O 7−δ pyrochlores was determined. According to works, − Li + , as well as Bi 3+ , enhances the luminescence properties of the pyrochlores due to modification of the local crystal structure and creation of a charge imbalance compensated by the host material.…”

Exploring color tunable emission characteristics of Eu3+-doped La2(MoO4)3 phosphors in the glass–ceramic form

“…[10][11][12] Among the lanthanides, the Eu 3+ ion is well studied as a red-emitting activator ion due to 5 D 0 / 7 F J (J ¼ 0, 1, 2, 3, 4) emission transitions with predominant 5 D 0 / 7 F 2 transition, which falls in the red region of the visible spectrum. [13][14][15] The excitation and emission spectra of Eu 3+ ions give information on the local structure of the ions and their site symmetry. The presence of peaks due to 5 D 0 / 7 F 0 transition along with electric dipole (ED) 5 D 0 / 7 F 2 transition and magnetic dipole (MD) 5 D 0 / 7 F 1 transition gives a lot more information about the lattice site symmetry, especially the local environment in the rst co-ordination shell of the dopant ion.…”

“…16,17 In addition, the doping of impurity ions such as Bi 3+ , phosphate, sulphate and vanadate ions also inuences Eu 3+ ion emissions due to energy transfer or change in the local crystal structure. 14,15 Therefore, a structure-property relationship will not only help to optimize the emission properties for a better performance of phosphor materials, but also give a lot of information about the local structure at atomic scale, which is otherwise difficult to get from studies like XRD. Further, various Judd-Ofelt (JO) parameters, viz., U J (J ¼ 2, 4), non-radiative emission rates (A NR ), radiative lifetimes (s R ) and non-radiative lifetimes (s NR ) demonstrated for many Eu 3+ -doped phosphors by our group earlier will give additional information about the photophysics of the Eu 3+ ion and the local structure.…”