Luminescence characteristics of Dy3+ doped Gd2O3-CaO-SiO2-B2O3 scintillating glasses

Kaewkhao, J.,Wantana, N.,Kaewjaeng, S.,Kothan, S.,Kim, H.J. Elsevier 2016 Journal of rare earths Vol.34 No.6

<P>Glasses were prepared from the compositions of 25Gd(2)O(3)-10CaO-10SiO(2)-(55-x)B2O3-xDy(2)O(3) (where x is 0.0 mol.%-1.0 mol.%) by the conventional melt-quenching technique at 1400 degrees C. The results demonstrated the increase in the glass density with respect to the increase in the doping concentrations of Dy2O3. Nine absorption bands were observed. The emission spectra of the developed glass showed two strong peaks at 577 nm (F-4(9/2)-> H-6(13/2)) and 482 nm (F-4(9/2)-> 6H(15/2)). The highest emission intensity was observed from the developed glass prepared at 0.4 mol.% of Dy2O3, as the efficient energy transfer took place from Gd3+ to Dy3+. From the X-ray induced optical luminescence, the emission spectra were identical to those from PL measurements, but with the highest intensity observed from the glass quenched at 0.45 mol.% of Dy2O3. Finally, the integral scintillation efficiency of the developed glass was determined at 27% of that of the commercially available BGO crystal.</P>

Interaction of 662 keV Gamma-rays with Bismuth-based Glass Matrices

Kaewkhao, J.,Kirdsiri, K.,Limkitjaroenporn, P.,Limsuwan, P.,Park, Jeongmin,Kim, H. J. Korean Physical Society 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.2

Interaction of 662 keV Gamma-rays with Bismuth-based Glass Matrices

J. Kaewkhao,K. Kirdsiri,P. Limkitjaroenporn,P. Limsuwan,박정민,김홍주 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.22

In this work, the Bi_2O_3-SiO_2 glass system was synthesized by using the melt-quenching method. The radiation shielding properties of the glass samples at various levels of bismuth content were measured at 662 keV by usage a ^(137)Cs radioactive source, and comparisons were made with values theoretically calculated by usage WinXCom. The experimentally obtained values were generally in good agreement with the theoretical ones. Furthermore, a comparison was made to a lead-borate glass system with the same level of additive. The radiation shielding properties were found to be improved with increasing Bi_2O_3 concentration. The different values of Compton scattering yielded a higher total mass attenuation coefficient for the bismuth-silicate glass than for the bismuth-borate glass. These results reflect the potential usefulness of bismuth-based glasses as new materials for lead-free radiation-shielding glasses.

Optical and luminescence properties of Li₂O?Gd₂O₃?MO?B₂O₃?Sm₂O₃ (MO?Bi₂O₃, BaO) glasses

Zaman, F.,Kaewkhao, J.,Rooh, G.,Srisittipokakun, N.,Kim, H.J. Elsevier Sequoia 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.676 No.-

Spectroscopic properties of Sm<SUP>3+</SUP> ion in borate based glasses (Li<SUB>2</SUB>O?Gd<SUB>2</SUB>O<SUB>3</SUB>-MO-B<SUB>2</SUB>O<SUB>3</SUB> where MO?Bi<SUB>2</SUB>O<SUB>3</SUB>, BaO) have been investigated. Glasses are prepared by melt quenching technique and their properties are investigated using different techniques which include absorption, photoluminescence (PL), X-ray excited luminescence (XEL) spectra and decay rate analysis. Furthermore, other related physical and optical properties have been calculated. From absorption spectra the most intense and hyper sensitive transition is <SUP>6</SUP>H<SUB>5/2</SUB> → <SUP>6</SUP>P<SUB>3/2</SUB> at 403 nm. Under 403 nm excitation wavelength, four prominent emission peaks are observed at 563, 599, 645 and 707 nm. For Sm<SUP>3+</SUP> ion the quenching points are observed at 2.0 and 1.5 mol% of LGBiBSm and LGBaBSm, respectively. Measured XEL spectra of the glass samples are found in agreement with that of PL emission spectra. The experimental decay rate follows non exponential behavior at higher concentrations and well fitted to the IH model for S = 6. The obtained color coordinates of the prepared glass matrix fall in the orange region of the CIE diagram. Comparing with LGBiBSm glass, LGBaBSm is transparent and exhibits long decay time value. Moreover, LGBaBSm shows high luminescence properties with excellent energy transfer from the host matrix to the luminescence center. On the basis of the observed properties of the developed glasses, it is expected that they will be best for the orange LEDs.

Scintillation and Luminescence Properties of Sm3+-Activated Lu2O3-CaO-SiO2-B2O3 (LuCSB) Scintillating Glasses

K. Kirdsiri,J. Kaewkhao,박정민,하대훈 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.6

Lutetium (Lu) is a high atomic number material and readily interacts with X-rays, which makes it a good scintillation material. In this work, Lu-glass scintillators from the series xSm2O3 : 25Lu2 O3 : 10SiO2 : 10CaO : (55-x)B2O3 (LuCSB) were synthesized at 1500 ◦ C by using a simple melt quenching technique. The influence of the Sm3+ ion on their physical, optical, photo-, X-rayand proton-induced properties has been characterized. The amorphous nature of the samples was confirmed by using X-ray diffraction. The density and the molar volume were found to be increased at higher concentrations of Sm3+. The X-ray- and the proton-induced emission spectra of the Sm3+:LuCSB glasses showed an intense reddish-orange emission around 604 nm (4G5/2 → 6H7/2), which matched the photoluminescence (PL) emission spectrum well. Among the prepared glasses, the 1.0-mol% Sm3+ ion-activated LuCSB glass exhibited the highest value of the characteristic emission parameters. The X-ray-induced luminescence of the LuCSB glass was also compared with that of a commercial bismuth germinate Bi4Ge3O12 (BGO) crystal.

Development of lithium yttrium borate glass doped with Dy³⁺ for laser medium, W-LEDs and scintillation materials applications

Kaewnuam, E.,Wantana, N.,Kim, H.J.,Kaewkhao, J. North-Holland 2017 Journal of non-crystalline solids Vol.464 No.-

<P>Lithium yttrium borate glasses doped with dysprosium ion (Dy3+) were synthesized by a melt-quenching technique. Glasses were studied the physical properties such as density, molar volume and refractive index. The absorption, excitation and emission spectra, including decay curve were monitored to study the luminescence properties. The X-ray induced luminescence and temperature dependence luminescence spectra was also investigated. The experimental results show that Dy3+ probably acts as modifier in this glass because molar volume increased with increasing of Dy3+ doped content. Glasses absorbs photon in visible light and near-infrared region with Dy3+ transition from H-6(15/2) ground state. Glass performs the strongest emission at 575 nm (F-4(9/2) -> H-6(13/2)) with 388 nm excitation wavelength. The intensity of emission increases with increasing of Dy2O3 concentration until 1.00 mol% after that it decreases by resonance energy transfer and cross-relaxation processes. The photo emission is white light confirmed by CIE 1931 chromaticity and UV lamp excitation. Decay curve, fitted by Inokutie-Hirayama model (S = 6), shows the non-exponential pattern which indicates a dipole-dipole interaction between Dy3+ donor and acceptor in glass. Judd-Ofelt analysis exhibits an interesting potential for using glass as laser medium with 575 nm emitting. X-ray induced luminescence spectra perform the sharp emission band of Dy3+ after accepted energy transfer from host glass. This is a good sign for scintillation potential. Temperature dependence luminescence spectra show the strong emission at low temperature condition. Emission intensity relates linearly with the temperature change. This Dy3+ doped glass can be developed for using as photonic materials in the display, white-light emitting diode, laser device, scintillation detector and even temperature sensor. (C) 2017 Elsevier B.V. All rights reserved.</P>

White light emission of dysprosium doped lanthanum calcium phosphate oxide and oxyfluoride glasses

Luewarasirikul, N.,Kim, H.J.,Meejitpaisan, P.,Kaewkhao, J. Elsevier 2017 Optical materials Vol.66 No.-

<P><B>Abstract</B></P> <P>Lanthanum calcium phosphate oxide and oxyfluoride glasses doped with dysprosium oxide were prepared by melt-quenching technique with chemical composition 20La<SUB>2</SUB>O<SUB>3</SUB>:10CaO:69P<SUB>2</SUB>O<SUB>5</SUB>:1Dy<SUB>2</SUB>O<SUB>3</SUB> and 20La<SUB>2</SUB>O<SUB>3</SUB>:10CaF<SUB>2</SUB>:69P<SUB>2</SUB>O<SUB>5</SUB>:1Dy<SUB>2</SUB>O<SUB>3</SUB>. The physical, optical and luminescence properties of the glass samples were studied to evaluate their potential to using as luminescence materials for solid-state lighting applications. The density, molar volume and refractive index of the glass samples were carried out. The optical and luminescence properties were studied by investigating absorption, excitation, and emission spectra of the glass samples. The absorption spectra were investigated in the UV–Vis–NIR region from 300 to 2000 nm. The excitation spectra observed under 574 nm emission wavelength showed the highest peak centered at 349 nm (<SUP>6</SUP>H<SUB>15/2</SUB> → <SUP>6</SUP>P<SUB>7/2</SUB>). The emission spectra, excited with 349 nm excitation wavelength showed two major peaks corresponding to 482 nm blue emission (<SUP>4</SUP>F<SUB>9/2</SUB> → <SUP>6</SUP>H<SUB>15/2</SUB>) and 574 nm yellow emission (<SUP>4</SUP>F<SUB>9/2</SUB> → <SUP>6</SUP>H<SUB>13/2</SUB>). The experimental lifetime were found to be 0.539 and 0.540 for oxide and oxyfluoride glass sample, respectively. The x,y color coordinates under 349 nm excitation wavelength were (0.38, 0.43) for both glass samples, that be plotted in white region of CIE 1931 chromaticity diagram. The CCT values obtained from the glass samples are 4204 K for oxide glass and 4228 K for oxyfluoride glass corresponding to the commercial cool white light (3100–4500 K). Judd-Ofelt theory had also been employed to obtain the J-O parameters (Ω<SUB>2</SUB>, Ω<SUB>4</SUB> and Ω<SUB>6</SUB>), oscillator strength, radiative transition possibility, stimulated emission cross section and branching ratio. The Ω<SUB>2</SUB> > Ω<SUB>4</SUB> > Ω<SUB>6</SUB> trend of J-O parameters of both glass samples may indicate the good quality of a glass host for using as optical device application. Temperature dependence of emission spectra was studied from 300 K to 10 K and found that the intensity of the emission peak was found to be increased with decreasing of the temperature. The results of the investigations in this work confirmed that the present Dy-doped lanthanum calcium phosphate oxide and oxyfluoride glasses perform high potential for using as efficient luminescence materials for solid-state lighting applications, especially for white LEDs. Furthermore, the oxyfluoride glass sample provides more luminescence potential than the oxide glass sample.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lanthanum calcium phosphate oxide and oxyfluoride glasses doped with Dy<SUP>3+</SUP> were studied. </LI> <LI> Emission spectra showed two major peaks corresponding to 482 and 574 nm. </LI> <LI> Both glasses corresponding to the commercial cool white light (3100–4500 K). </LI> <LI> Judd-Ofelt theory had also been employed to obtain the J-O parameters. </LI> <LI> Oxyfluoride glass provides more luminescence potential than the oxide glass. </LI> </UL> </P>

Luminescence Property of Rare-earth-doped Bismuth-borate Glasses with Different Concentrations of Bismuth and Rare-earth Material

J. M. Park,P. Limsuwan,J. Kaewkhao,김홍주,김성환 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.2

Bismuth-borate glass scintillators have high density and good radiation hardness. Thus, if they are highly luminescent, they can be applied in astrophysics, high-energy and nuclear physics, homeland security, radiation detection and medical imaging. Bismuth-borate glasseswith the formula xBi₂O₃:(100 − x)B₂O₃ (x = 30, 50, and 66.7 mol%) were fabricated and doped with Nd, Er, Dy, Pr, Sm, Ho, Gd, and Ce in different dopant concentrations by using the melt-quenching technique. The X-ray emission spectra for the bismuth-borate glasses were measured and showed that only Sm-, Dy-, and Nd-doped glass scintillators had noticeable luminescence. Also, we measured the photo-luminescence and the proton-induced emission spectra. We obtained the result that Sm- and Dy- doped glass scintillators emitted luminescence. The emission peaks of the Sm- doped glass were 569, 598, 641, and 708 nm and were due to (⁴G_5/2 → ⁶H_<i>J</i> ) (<i>J</i> = 5/2, 7/2, 9/2, 11/2) transitions, respectively. The emission peaks of the Dy- doped glass were at 485 nm (⁴F_9/2 → ⁶H_15/2), 575 nm (⁴F_9/2 → ⁶H_13/2), 660 nm (⁴F_9/2 → ⁶H_11/2), and 755 nm (⁴F_9/2 → ⁶H_9/2 + ⁶H_11/2), and that of the Nd-doped glass was at 895 nm due to the (⁴F_3/2 → ⁴I_9/2) transition. The luminescence intensities were compared in terms of different Bi concentrations and dopant concentrations.

Optical Properties in the Visible Luminescence of SiO2:B2O3:CaO:GdF3 Glass Scintillators Containing CeF3

J. M. PARK,김홍주,Sujita Karki,J. Kaewkhao,B. Damdee,S. Kothandaraman,S. Kaewjaeng 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.71 No.11

CeF3-doped silicaborate-calcium-gadolinium glass scintillators, with the formula 10SiO2:(55- x)B2O3:10CaO:25GdF3:xCeF3, were fabricated by the melt-quenching technique. The doping concentration of the CeF3 was from 0.00 mol% to 0.20 mol%. The optical properties of the CeF3 doped glass scintillators were studied by using various radiation sources. The transition state of the CeF3- doped glass scintillators studied by using the absorption and photo-luminescence spectrum results. The X-ray, photo, proton and laser-induced luminescence spectra were also studied to understand the luminescence mechanism under various conditions. To understand the temperature dependence, the laser-induced luminescence and the decay component of the CeF3-doped glass scintillator were studied while the temperature was varied from 300 K to 10 K. The emission wavelength spectrum showed from 350 nm to 55 nm under various radiation sources. Also the CeF3-doped glass scintillator have one decay component as 34 ns at room temperature.

X-ray and Proton Luminescences of Bismuth-borate Glasses

박정민,김홍주,김성환,천종규,J. Kaewkhao,P. Limsuwan,S. Insiripong 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.22

Heavy scintillators with good radiation hardness and low cost can be applied in high -energy physics, astrophysics, homeland security and radiation detection. It is possible to make heavy-iondoped glass scintillators that can meet these requirements. We fabricated bismuth-borate glasses, Bi_2O_3(30) : B_2O_3(70), doped with CeO_2, Nd_2O_3, Er_2O_3, Dy_2O_3, and Pr_2O_3 in difference concentrations by using the melt-quench technique. An X-ray luminescence study showed that only Dy_2O_3-doped glass emitted luminescence with a peak at 575 nm. Absorption spectra o f the Dy_2O_3-doped glass were studied to understand the optical property. Proton luminescence of Dy_2O_3-doped glass was studied by using the 45-MeV proton beam from the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). The results for the proton and the X-ray luminescences were compared.