Thermal study in Eu3+-doped boehmite nanofibers and luminescence properties of the corresponding Eu3+:Al2O3

Abstract

Eu 3? -doped boehmite nanofiber materials with different Eu 3? concentrations were synthesized without any surfactant, and followed by a series of characterizations. It was found that the boehmite nanofibers became coarser with the increase of Eu 3? concentration, which resulted in a gradual decrease of their specific surface areas. Moreover, the thermal stability of the boehmite nanofibers was studied by thermogravimetry-differential scanning calorimetry. All materials showed the phase transition from c-Al 2 O 3 to other forms. Yet the transition temperature was increased with the increase of Eu 3? concentration. The Eu 3? -doped boehmite nanofibers with the maximum Eu 3? concentrations showed the best thermal stability. Photoluminescence spectra showed that the 2 mol% of doping concentration of Eu 3? ions in Eu 3? :-Al 2 O 3 nanofiber was optimum.

Photoluminescence imaging of europium (III)‐doped γ‐Al2O3 nanofiber structures

“…After thermal treatment at 800°C, all XRD patterns of the three samples were critically changed and the new peaks were commonly found at 2θ = 39.5, 45.9, and 67.0°, attributed to the (111), (002), and (022) crystal planes in the cubic (Fm‐3 m) phase of γ ‐Al 2 O 3 (ref. # 98–003‐0267); this was consistent with findings in the published literature . Yu and colleagues also reported a γ ‐Al 2 O 3 single phase prepared by the sol–gel method, followed by thermal annealing at 900–1100°C .…”

“…Light (200–900 nm) absorption by γ‐Al 2 O 3 was excluded because of a larger band gap of 7.6 ± 0.1 eV (~163 nm) . For 800°C‐calcined Eu(III)‐doped Al 2 O 3 microspheres, a strong broad band was reported to be observed at ~255 nm . As the calcination temperature was increased, the peak position (nm) was found to be increased and positioned at 310 nm for the sample calcinated at 1300°C .…”

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

“…and Dy 3? rare earth ions are widely used as the activator and co-activator to improve materials performance, such as photoluminescence properties [7,8]. Eu 3?…”

Synthesis and photoluminescence properties of Eu3+-doped ZrO2 hollow spheres

“…[1][2][3][4][5][6] The macroscopic properties of phosphors, such as the emission spectrum or the luminous efficiency, rely on their composition, crystal structure, and morphology. [7][8][9][10][11][12] Extensive work has been devoted to the development of effective morphology-controlled methods to synthesize functional materials with complex three-dimensional (3D) hierarchical architectures, such as Fe 2 O 3 flower-like microspheres, 13 urchin-like WO 3 and MnWO 4 microstructures, 14,15 cactus-like b-Ga 2 O 3 microarchitectures, 16 dandelion-like ZnO and CuO architectures, 17,18 3D hierarchical MWO 4 (M 5 Mn, Bi, Ba, and Pb), and MMoO 4 (M 5 Fe, Pb, and Ba) superstructures, 9,[19][20][21][22][23] which have been fabricated from low dimensional nanobuilding units by bottom-up approaches. Since sphere morphology of phosphor is favorable for high brightness and high resolution, spherical structured particles have been interestingly studied in these years.…”

“…Since sphere morphology of phosphor is favorable for high brightness and high resolution, spherical structured particles have been interestingly studied in these years. [16][17][18] The selection of host materials for RE ions is crucial to obtain large luminescence signals. 14 Materials with low phonon energies present small nonradiative losses owing to the multiphonon relaxation, and consequently, the luminescence efficiency is enhanced.…”