Photoluminescence and mechanoluminescence investigation of bluish-green afterglow SrMgAl10O17:Ce3+ phosphor (original) (raw)
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Optical Materials, 2016
SrMgAl 10 O 17 :Eu 2+ phosphor has been synthesized by combustion method using urea as a fuel. Thermoluminescence (TL) and mechanoluminescence (ML) properties of synthesized phosphors under gamma irradiation were reported and discussed in this paper. The structural and morphological studies were done using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Photoluminescence emission spectrum is obtained at 460 nm. Thermoluminescence glow curves of synthesized phosphor show a broad peak, which has been deconvoluted into three peaks and activation energies were calculated using peak shape method. Total mechanoluminescence (ML) intensity increases linearly with gamma doses.
Journal of Non-crystalline Solids, 2009
Strong blue-green light emitting Eu doped SrAl 2 O 4 phosphor was synthesized by a low-temperature initiated, self-propagating and gas producing combustion process in a very short time (<5 min). The prepared powder was characterized by X-ray diffraction, Fourier-transform infrared spectrometry and scanning electron microscopy. The excitation spectrum shows a peak at 397 nm. Upon excitation at 397 nm, the emission spectrum exhibits a well defined broad band with maximum at 493 nm corresponding to 4f 6 5d ? 4f 7 transition. Electron paramagnetic resonance (EPR) measurements at X-band showed low field signals due to Eu 2+ ions in SrAl 2 O 4 :Eu.
22 O 36 :Ce 3+ ,Dy 3+ phosphors were synthesized by urea-assisted combustion method. The identification of phase and morphology of the prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Photoluminescence excita-tion (PLE) and emission spectra of the as-prepared samples were investigated. Photoluminescence studies revealed that the luminescence intensity of Ce 3+ ion increases with increasing concentration in Sr 2 MgAl 22 O 36 :Ce 3+ and no concentration quenching have been witnessed. Similar trend was observed for Sr 2 MgAl 22 O 36 :Dy 3+ with increasing Dy 3+ concentration. The energy transfer from Ce 3+ to Dy 3+ in Sr 2 MgAl 22 O 36 host has been achieved successfully to produce white light emission. The calculated Commission Internationale de L′Eclairage (CIE) chromaticity coordinates for the Sr 2 MgAl 22 O 36 :Ce 3+ , Dy 3+ phosphor are (x = 0.302, y = 0.357). The values of CIE chromaticity coordinates and correlated color temperature (CCT) of 6798 K endorse Sr 2 MgAl 22 O 36 :Ce 3+ , Dy 3+ phosphor as potential candidate for cool white-light emission.
Investigations on the luminescence properties of Na0.34Ca0.66Al1.66Si2.34O8:Eu2+/Eu3+/Sm3+ phosphors
Solid State Sciences, 2015
Rare Earth doped-phosphate glasses have received a great deal of attention on research because of their applications in biomaterial engineering, however, little to no attention has been given to potential luminescent properties from "heating" these materials when exposed to ionizing radiation. This paper aims to presents results on investigations of Thermoluminescent (TL) and Optically Stimulated Luminescence (OSL) properties of the Er 3+-doped phosphate glasses produced at the Physics Department of Federal University of Juiz de Fora on a characterization for beta radiation dosimetry. It was used a RISØ TL/OSL reader and its coupled 90 Sr/ 90 Y beta source. The experimental findings indicate that the mate bands on 350-380nm from Er 3+. Further investigations are being carried out on its applications to other types and qualities of radiation.
Effect of Al/Sr ratio on the luminescence properties of SrAl2O4:Eu2+, Dy3+ phosphors
Recent studies have brought out many phosphors like Eu 2+ , Dy 3+ -doped alkaline earth aluminates. The trivalent Dy 3+ ions as co-dopants greatly enhance the duration and intensity of persistent luminescence. These phosphors show excellent properties, such as high quantum efficiency, long persistence of phosphorescence, good stability and suitable color emission.
Journal of Materials Science: Materials in Electronics, 2015
A series of rare earth doped and co-doped distrontium magnesium di-silicate phosphors namely: Sr 2 MgSi 2 O 7 :Ce 3? , Sr 2 MgSi 2 O 7 :Eu 2? and Sr 2 MgSi 2 O 7 :Eu 2? , Ce 3? were prepared by the solid state reaction method. The crystal structures of sintered phosphors were an akermanite type structure which belongs to the tetragonal crystallography. The chemical compositions of sintered phosphors were confirmed by energy dispersive X-ray spectroscopy (EDS). Under the ultraviolet excitation, the emission spectra of both Sr 2 MgSi 2 O 7 :Eu 2? and Sr 2 MgSi 2 O 7 :Eu 2? , Ce 3? phosphors were composed of a broad band peaking at 460 nm, belonging to the broad emission band. When the Sr 2 MgSi 2 O 7 :Eu 2? phosphor is co-doped with Ce 3? ions, thermouminescence, photoluminescence, afterglow and mechanoluminescence (ML) intensity were strongly enhanced. The Sr 2 MgSi 2 O 7 :Eu 2? phosphor showed some afterglow with short persistence time. By incorporation of Ce 3? ions, an efficient energy transfer from Ce 3? to Eu 2? was found and emission intensity of Sr 2 MgSi 2 O 7 :Eu 2? was enhanced. The ML intensities of Sr 2 MgSi 2 O 7 :Ce 3? , Sr 2 MgSi 2 O 7 :Eu 2? and Sr 2 MgSi 2 O 7 :Eu 2? , Ce 3? phosphors were proportionally increased with the increase of impact velocity, which suggests that these phosphors can be used as sensors to detect the stress of an object. Thus the present investigation indicates that the piezoelectricity is responsible to produce ML in prepared phosphors.
Luminescence Properties of Sr2MgSi2O7:Eu2+, Ce3+ Phosphor by Solid State Reaction Method
Physics Procedia, 2015
The Sr 2 MgSi 2 O 7 :Eu 2+ , Ce 3+ phosphor was prepared by solid state reaction method, boric acid (H 3 BO 3) was added as flux. The phase structure of Sr 2 MgSi 2 O 7 :Eu 2+ , Ce 3+ phosphor was akermanite type structure which belongs to the tetragonal crystallography with space group P4̅ 2 1 m, this structure is a member of the melilite group and forms layered compound. EDX and FTIR spectra confirm the present elements in Sr 2 MgSi 2 O 7 :Eu 2+ , Ce 3+ phosphor. Three peaks in excitation spectra were found at 253, 293, 325nm and corresponding emission peak was recorded at 465nm, belonging to the broad emission ascribed to the 4f 6 5d 1 →4f 7 transition of Eu 2+. The ML intensity of prepared phosphor was increasing linearly with increases of mechanical load.
Research on Chemical Intermediates, 2014
Sr 2 MgSi 2 O 7 :Eu 2? , Dy 3? and Ca 2 MgSi 2 O 7 :Eu 2? , Dy 3? phosphors were synthesized by the high-temperature solid-state reaction method. The phase structure of the prepared phosphors was of akermanite type, which belongs to the tetragonal crystallography. The EDX and FTIR spectra confirm the presence of elements in prepared phosphors. Sr 2 MgSi 2 O 7 :Eu 2? , Dy 3? and Ca 2 MgSi 2 O 7 :Eu 2? , Dy 3? phosphors would emit blue and green light; the main emission peaks that appeared at 465 and 535 nm belong to the broad emission band ascribed to the 4f 6 5d 1 ? 4f 7 transition. Decay graph indicates that both the phosphors have fast decay and slow decay. Investigation into afterglow property showed that the Sr 2-MgSi 2 O 7 :Eu 2? , Dy 3? phosphor held better afterglow property than Ca 2 MgSi 2 O 7 :-Eu 2? , Dy 3? phosphors. ML measurements showed a linear increase in the ML intensity with the impact velocity of the moving piston.
Journal of Alloys and Compounds, 2012
Eu 2+ and Eu 2+ -Mn 2+ codoped (Ba,Sr)Mg 2 Al 6 Si 9 O 30 phosphors have been synthesized by solid state reaction, and their luminescent properties are investigated. Under the excitation of 330 nm, it is observed that the emission of Eu 2+ consists of two emission bands, located at around 370 and 450 nm, which are attributed to two Eu 2+ centers (Eu 2+ (I) and Eu 2+ (II)) ions substituting for two different Ba 2+ and Mg 2+ sites, respectively. As Sr 2+ gradually substitutes Ba 2+ , the emission bands of Eu 2+ (I) shift to longer wavelength whereas the emission bands of Eu 2+ (II) exhibit no change. This phenomenon is discussed in terms of the crystal-field strength. A detail analysis on the energy transfer from Eu 2+ to Mn 2+ in SrMg 2 Al 6 Si 9 O 30 host is presented, which indicates the energy of the red emission of Mn 2+ is derived mainly from Eu 2+ (I). We have also demonstrated that BaMg 2 Al 6 Si 9 O 30 :Eu 2+ , Mn 2+ exhibits better thermal quenching properties than that of SrMg 2 Al 6 Si 9 O 30 :Eu 2+ , Mn 2+ because of bigger activation energy.
Photoluminescence and gamma-ray irradiation of SrAl 2O 4:Eu 2+and Y 2O 3:Eu 3+ phosphors
Journal of Physics and Chemistry of Solids, 2007
Y 2 O 3 :Eu 3+ phosphor is a very attractive material for use as a red phosphor in many fields. SrAl 2 O 4 :Eu 2+ belongs to long lasting phosphor (LLP) and it is a useful bluish-green luminescence material, which can also be a promising candidate as a simple and easy-touse radiation detection element for visual display of two dimensional radiation distributions. In the present study, both these two kinds of phosphors were synthesized using high temperature solid state reactions. In our work, the influence of gamma-ray irradiation on the properties of these two kinds of phosphors was studied by comparing photoluminescence, brightness and the decay curve of unirradiated and gamma-ray-irradiated samples. Conclusions from the present work can be briefly summarized as follows. In irradiated samples, the brightness is decreased without sensible change in the wavelength distribution of the luminescence spectrum and in the decay kinetic upon gamma exposure. Moreover, the emission due to Eu 3+ -Eu 2+ conversion in Y 2 O 3 :Eu 3+ phosphors was not observed in our sample after irradiation to high exposure. Also the brightness of SrAl 2 O 4 :Eu 2+ phosphor turned out to decrease after the exposition to ionizing radiation while the luminescence wavelength distribution remained unchanged. The reason for the effect of gamma-ray irradiation on the properties of phosphors is also discussed in the paper. r