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Enhancement of gamma and X-ray shielding behaviors in ZnO-B2O3 glasses via La2O3 addition: Experimental and theoretical investigations
(2025-12-01)
Yabsantia, S.
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Wantana, N.
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Chusin, T.
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Kaewjaeng, S.
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Ornketphon, O.
Radiation shielding materials are crucial for reducing radiation exposure. Traditional materials such as lead, and concrete pose challenges related to toxicity and lack of transparency. This study aimed to assess the effects of lanthanum oxide (La<inf>2</inf>O<inf>3</inf>) addition on physical, optical, and radiation shielding properties of ZnO–B<inf>2</inf>O<inf>3</inf> glass systems. Glass samples of (80-x)B<inf>2</inf>O<inf>3</inf>–20ZnO-xLa<inf>2</inf>O<inf>3</inf> (x = 5–20 mol%) were prepared using the melt-quenching technique and characterized for density, molar volume, refractive index, transmittance and X-ray diffraction (XRD). Gamma-ray shielding performance was evaluated using the Compton scattering method with a Cs-137 source and NaI(Tl) detector, alongside theoretical data from WinXCOM. X-ray shielding capabilities were determined through experimental transmission measurements and Monte Carlo simulations (PHITS) across effective energies ranging from 30.40 to 44.21 keV. Increasing La<inf>2</inf>O<inf>3</inf> content (5–20 mol%) resulted in higher density (2.89–3.63 g/cm3), slightly increased molar volume (29.37–33.98 cm3/mol), and higher refractive index (1.58–1.65). All La<inf>2</inf>O<inf>3</inf>-added glasses exhibited ∼75 % transmittance in the visible region. XRD analysis indicated amorphous characteristics for all samples. For gamma rays, both experimental and theoretical results agreed well, showing improved shielding with higher La<inf>2</inf>O<inf>3</inf> levels. For lowest gamma-ray energy, the 20 mol% sample had the highest mass attenuation coefficient (μ<inf>m</inf>) of 0.21 cm2/g, lowest half value layer (HVL) of 0.89 cm, and shortest mean free path (MFP) of 1.29 cm. For X-rays, PHITS simulations and experiments also aligned, with μ<inf>m</inf> up to 4.21 cm2/g (at 30.40 keV), HVL of 0.05 cm, and MFP of 0.07 cm. These findings suggest that La<inf>2</inf>O<inf>3</inf> addition enhances both gamma and X-ray shielding effectiveness. In conclusion, the study highlights the potential of La<inf>2</inf>O<inf>3</inf>-added ZnO–B<inf>2</inf>O<inf>3</inf> glass as an alternative shielding material, with future research aimed at further improving its shielding performance.
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Ca co-doped CsI(Tl) crystal scintillator for γ- and X-ray detecting applications
(2025-01-01)
Tariwong, Y.
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Kim, H. J.
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Quang, Nguyen Duy
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Khan, Arshad
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Daniel, D. Joseph
The vertical Bridgman method is used for the growth of single-doped CsI(Tl) and CsI(Tl:Ca) crystals, which has been evaluated for feasible applications in X-ray imaging and radiation detection. The powder XRD technique study reveals a single-crystalline phase of the grown crystal. The emission spectra show a broad emission band with a maximum of 540 nm under X-ray excitation, along with the characteristic emissions that arose from the Tl+ intra-center transition. The scintillation qualities of the grown crystal were studied via the pulse height spectra, scintillation light yield, energy resolution, and scintillation decay time. Pulse shape discrimination (PSD) was investigated under γ-rays and α-particles excitation sources. Moreover, the X-ray imaging application was investigated by an X-ray synchrotron at the Synchrotron Light Research Institute to study the performance of the grown crystal. These preliminary investigations suggest that the grown CsI(Tl:Ca) crystal can be one of the promising crystals for γ- and X-ray detecting applications.
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Structural, optical, luminescence spectroscopy and radiation shielding properties of Eu3+:borophosphotellurite glasses
(2024-10-01)
Masthanaiah, E.
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Basavapoornima, Ch
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Lokanadham, R.
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Pecharapa, Wisanu
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Kaewkhao, J.
Recently much effort is being paid to study the rare earth ions in multi component glass formers as they exhibit high enhancement in the efficiency of luminescence properties. In this direction, the present study focuses on the preparation and analysis of novel glass batches with composition of (in mol %) BPTCZEu: 40B<inf>2</inf>O<inf>3</inf>+20P<inf>2</inf>O<inf>5</inf>+15TeO<inf>2</inf>+ 10CaO+(15−x)ZnO + xEu<inf>2</inf>O<inf>3</inf>, x = 0.1, 0.5, 1.0, 1.5, 2.0 and 2.5. The important spectroscopic techniques such as optical absorption, luminescence, excitation and decay curves are taken to analyse the BPTCZEu glasses. Luminescence spectrum of BPTCZEu comprise of emission from excited (5D<inf>0</inf>) to the lower multiplets (7F<inf>J</inf> (J = 0−4)), among these, 5D<inf>0</inf> → 7F<inf>2</inf> (red luminescence) at 612 nm found to be very intense. Judd−Ofelt characteristics, Ω<inf>2</inf>, Ω<inf>4</inf> and Ω<inf>6</inf>, were derived from different constraints. To know the site symmetry around Eu3+, the fluorescence intensity ratio of 5D<inf>0</inf> → 7F<inf>2</inf> vs. 5D<inf>0</inf> → 7F<inf>1</inf> were analysed. Exciting 7F<inf>0</inf> → 5L<inf>6</inf> and monitoring 5D<inf>0</inf> → 7F<inf>2</inf>, the lifetime of 5D<inf>0</inf> level is determined to be 2 ms which is independent of Eu3+ content. The colour coordinates for all the Eu3+ concentrations are estimated to fall in the reddish−orange region. Theoretical radiation shielding results showed that substituting Eu<inf>2</inf>O<inf>3</inf> for ZnO in the glasses lowers photon number that can pass via the material, enhancing the glass system's trend to shield high energy radiation. These stimulated results are compared with experimental measurements of mass attenuation coefficient with respect to energy up to 662 KeV using Cs−137 source. All these findings obtained from title glasses are compared and discussed with respect to reported Eu3+:glasses and no systematic variation has been noticed either with single, bi− or multi−component glass formers and therefore needs further systematic work to relate Eu−radiation−ligand interaction.
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Novel Tb3+ doped borophosphate glass scintillator for X-ray imaging
(2024-10-01)
Khrongchaiyaphum, F.
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Wantana, N.
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Kaewnuam, E.
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Pakawanit, P.
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Phoovasawat, C.
In this study, we introduce an efficient green-emitting material made from Tb3+ doped borophosphate scintillating glass for X-ray imaging. An influence of Tb<inf>2</inf>O<inf>3</inf> concentration on the physical, optical, luminescent, and scintillation properties of glasses were investigated. The glass density and refractive index increase, while the molar volume and Tb3+ inter-ionic distance decreases with Tb<inf>2</inf>O<inf>3</inf> addition. These glasses absorb the photons in range of UV, Vis, and NIR. The excitations by UV and X-ray on glasses causes the strong green emission centered around 545 nm by the 5D<inf>4</inf> → 7F<inf>5</inf> transition of Tb3+. The energy transfer from Gd3+ to Tb3+ was occurred in this emission. The glass doped with 4 mol% of Tb<inf>2</inf>O<inf>3</inf> demonstrates the highest emission intensity at 545 nm due to the concentration quenching. The decay time of glasses are in few milliseconds. The integral X-ray scintillation efficiency of 4 mol% doped glass is 52% compared to that of BGO crystal. Additionally, this glass was proceeded in the X-ray imaging and yielded the image with satisfied resolution, characteristics and MTF values, compared to that obtained from YAG:Ce crystal. The developed glass has a potential for X-ray imaging applications, especially in the medical imaging, flaw detection, and security inspection.
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Eu2O3 doped silicoborate glasses for scintillation material application: Luminescence ability and X-ray imaging
(2023-12-01)
Intachai, N.
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Kothan, S.
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Wantana, N.
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Kaewjaeng, S.
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Pakawanit, P.
The glass samples were prepared by melt quenching method and changing Eu<inf>2</inf>O<inf>3</inf> concentrations following component of xEu<inf>2</inf>O<inf>3</inf> - 40Na<inf>2</inf>O - 7.5Gd<inf>2</inf>O<inf>3</inf> - 5SiO<inf>2</inf> - (47.5-x)B<inf>2</inf>O<inf>3</inf> (x = 0, 1, 2, 3 mol %). Density and molar volume tend to increase with increasing Eu<inf>2</inf>O<inf>3</inf> concentrations, corresponding to the larger non-bridging oxygen. Fourier transform infrared spectra (FTIR) results point out that the majority BO<inf>3</inf> borate group. The absorption spectra were represented in the length of UV-Vis and NIR region. The phonon energy of 3Eu:7.5Gd was 1280.54 cm−1, related to the borate glass host. The photoluminescence and X-ray-induced luminescence spectra of 3Eu:7.5Gd glass showed similar highest intensity at 613 nm (5D<inf>0</inf>→7F<inf>2</inf>). The photoluminescence quantum yield (PLQY) of 3Eu:7.5Gd glass shows the highest value at 85.70 %. The scintillation efficiency of 3Eu:7.5Gd glass was 17.51 % of bismuth germanate (BGO) crystal. The decay time owing to Eu3+ emission is 2.054 ms for 2Eu:7.5Gd glass. The highest energy transfer efficiency was 2 mol % of Eu<inf>2</inf>O<inf>3</inf> concentrations (η<inf>ET</inf> = 70 %). The CIE chromaticity coordinates of the glasses are placed in the reddish-orange area (0.65, 0.35). The spatial resolution of X-ray imaging study was 10 lp/mm. These results suggest that 3 mol % of Eu<inf>2</inf>O<inf>3</inf> doped silicoborate glass is capable of being a scintillator applied in the X-ray imaging system.
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Eu3+ Doped Na2O-Gd2O3-BaO-B2O3-P2O5 glasses for x-ray scintillator application
(2023-11-01)
Khrongchaiyaphum, F.
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Wantana, N.
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Kansirin, S.
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Pakawanit, P.
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Vittayakorn, N.
The Na<inf>2</inf>O-BaO-B<inf>2</inf>O<inf>3</inf>-P<inf>2</inf>O<inf>5</inf> doped with varying concentrations of Gd<inf>2</inf>O<inf>3</inf> and Na<inf>2</inf>O-Gd<inf>2</inf>O<inf>3</inf>-BaO-B<inf>2</inf>O<inf>3</inf>-P<inf>2</inf>O<inf>5</inf> glasses were doped with varying concentrations of Eu<inf>2</inf>O<inf>3</inf> (referred to as Eu:NGBaPB) and prepared using the melt-quenching technique. These glasses were analyzed comprehensively in the physical, optical, chemical groups and photo-/radio- luminescence properties. Furthermore, the X-ray imaging was operated to indicate the practical radiation detection of glass. The addition of Eu<inf>2</inf>O<inf>3</inf>, the density and refractive index of Eu:NGBaPB glasses increased, while the molar volume decreased. The glass exhibited photon absorption in the UV-NIR regions. Excitation from various sources such as X-ray, ultraviolet, and visible light resulted in a reddish-orange emission at approximately 613 nm, originating from the 5D<inf>0</inf>→7F<inf>2</inf> radiation state of Eu3+. Energy transfer occurred from Gd3+ to Eu3+ within the glass. These findings highlight the intriguing potential of the glass for applications as an X-ray scintillator.
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Fabrication luminescence and radiation shielding properties of Gd2O3–La2O3–ZnO–B2O3–Sm2O3 glasses
(2023-01-01)
Kaewjaeng, S.
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Kothan, S.
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Wantana, N.
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Kim, H. J.
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Rajaramakrishna, R.
The purpose of developing high transparency radiation shielding materials and luminescence materials with stoichiometric ratio of xGd<inf>2</inf>O<inf>3</inf>:10La<inf>2</inf>O<inf>3</inf>:10ZnO:(79-x) B<inf>2</inf>O<inf>3</inf>: 1Sm<inf>2</inf>O<inf>3</inf> where x = 0, 5, 10, 15, and 20 mol% using melt quenching technique. The physio-optical properties such as molar volume, density, concentration of rare-earth ions, polaron radius, inter-ionic radius, optical basicity, average distance between rare-earth ions, and optical packing density of the present glasses has been evaluated. The glass samples obtained show high density which is vital factor for radiation shielding. The absorption spectra show significant of bands Sm3+ ions. The FTIR results of Gd-La-Zn-B-Sm (Gd-1Sm) glass samples show signature borate BO<inf>3</inf> and BO<inf>4</inf> vibrational units in Gd-1Sm glass samples. The μ, μ<inf>m</inf>, HVL, TVL, and MFP were evaluated and showed that the values decrease with increasing X-ray energy whereas increase with an increase in Gd<inf>2</inf>O<inf>3</inf> content suggesting their potential use in X-ray diagnosis regions. The HVL value was compared with commercial windows, concrete, Serpentine and X-ray windows and found that the glasses doped with 10 mol%, 15mol%, and 20 mol% Gd<inf>2</inf>O<inf>3</inf> content showed better results than X-Ray windows at 10 kVp. The emission and excitation spectra of glass samples were studied and emission spectra show orange emission bands. The experimental lifetime analysis shows that the glass samples show decreasing trend from 1.161 to 1.128 ms with an increase in Gd3+ ions exhibiting single exponential nature.
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Na2O-Gd2O3-Al2O3-P2O5 glass scintillator doped with Dy3+: X-rays and proton responses
(2023-01-01)
Wantana, N.
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Kaewnuam, E.
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Tariwong, Y.
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Quang, Nguyen Duy
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Pakawanit, P.
Dy3+:Na<inf>2</inf>O-Al<inf>2</inf>O<inf>3</inf>-Gd<inf>2</inf>O<inf>3</inf>-P<inf>2</inf>O<inf>5</inf> (Dy:NAGP) glasses were fabricated to investigate the capability for radiation responses. The influence of Dy<inf>2</inf>O<inf>3</inf> concentration on glass properties was studied. The density and effective atomic number of glass increased with the addition of Dy<inf>2</inf>O<inf>3</inf> content. The glasses absorbed the photons in the ultraviolet, visible light, and near-infrared region. In photoluminescence (PL) spectra, the obvious yellow emission at 574 nm and blue emission at 482 nm of Dy3+ were both generated by the direct excitation and the Gd-Dy energy transfer. The PL decay time of glasses was in the millisecond order. There was thermal quenching observed in temperature-dependent luminescence (TDL). The radioluminescence (RL) and protonluminescence (PrL) represented the emission pattern of Dy3+ similarly to PL spectra. The concentration quenching caused 0.50Dy:NAGP glass with the highest PL and RL emission intensity. The X-ray imaging of developed glass using a synchrotron light source was successfully imaged for the first time.
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White Emission from Dy3+ Doped in ZnO–CaO–B2O3 for WLEDs Material Application
(2022-01-01)
Chaemlek, O.
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Kiwsakunkran, N.
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Boonpa, W.
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Wantana, N.
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Sareein, T.
The Dy3+ ions doped CaO-ZnO-B<inf>2</inf>O<inf>3</inf> glasses were synthesis by the melt quenching technique with various Dy<inf>2</inf>O<inf>3</inf> concentrations to investigation physical and optical properties. The results showed that the density and the molar volume trend to be increased along with increased Dy3+ concentration. The absorption spectra showed characteristic absorption peaks in the visible and near infrared regions. Judd–Ofelt (JO) intensity parameters have been obtained from the optical absorption spectra. The emission spectra of the glasses are illustrated the highest emission intensity at 574 nm wavelength, which corresponding to Dy3+ transition 4F<inf>9/2</inf>→6H<inf>13/2</inf> level. The decay time value decreased as the concentration of Dy<inf>2</inf>O<inf>3</inf> increased. The CIE 1931 chromaticity investigation showed that Dy3+ doped glasses emitted light with white color.
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Effect of Gd2O3 on the radiation shielding, physical, optical and luminescence behaviors of Gd2O3–La2O3–ZnO–B2O3–Dy2O3 glasses
(2021-08-01)
Kaewjaeng, S.
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Wantana, N.
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Kothan, S.
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Rajaramakrishna, R.
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Kim, H. J.
The present work focuses on lead-free glasses, their shielding behavior, and other optical studies. The glass composition with xGd<inf>2</inf>O<inf>3</inf>+10La<inf>2</inf>O<inf>3</inf>+10ZnO+(79-x) B<inf>2</inf>O<inf>3</inf>+1Dy<inf>2</inf>O<inf>3</inf>, x = 0, 5, 10, 15, 20 mol% were prepared to the characterization on physical, absorption spectra, photo-, radioluminescence, and radiation shielding properties. In the experimental results, the density of Gd-1Dy glass samples increases with the increase of Gd3+ ions concentrations. The ten-strong peak in the 5Gd-1Dy glass of absorption spectra in UV–Vis–NIR regions. The white photoluminescence spectra base of Gd-1Dy glass samples can be generated under excitation at 351 nm makes the strongest emission of Dy3+ ions and excitation through energy transfer from Gd3+ in Gd-1Dy glass samples with 275 and 351 nm. This strong white emission of Dy3+ ions also strong in x-ray luminescence and performs the integral scintillation efficiency of 33% when compared with BGO crystal. The radiation shielding properties in the diagnostic medicine energies region are correlated, the values of glass samples better than commercial windows, bricks, and concrete. The HVL values of glass sample at 15 and 20 mol% of Gd<inf>2</inf>O<inf>3</inf> has been found better than X-ray windows. The corollaries of Gd-1Dy glass samples can be a candidate for radiation detector and lead-free radiation shielding materials in future.

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