• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.570-573
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• 1999

High brightness (Y$_{x}$/Gd$_{1-x}$ )$_2$O$_3$:Eu Phosphor Particles were directly Prepared in the spray Pyrolysis by adding flux materials such as LiCl and HBO$_3$. The (Y$_{x}$/Gd$_{1-x}$ )$_2$O$_3$:Eu particles prepared from solution with flux material had higher PL (photoluminescence) intensities than those prepared from solution without flux. In the spray pyrolysis, the flux acts as promoter of the growth of crystallite and activation of doping material as in the solid state reaction method. Additionally, the flux improved PL intensity of (Y$_{x}$/Gd$_{1-x}$ )$_2$O$_3$:Eu phosphor particles by densifying the internal structure and eliminating the defect existing inside and surface of (Y$_{x}$/Gd$_{1-x}$ )$_2$O$_3$:Eu phosphor particles.r particles.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.1051-1052
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• 2004

• Journal of the Korean Vacuum Society
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• v.12 no.4
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• pp.275-280
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• 2003

Epitaxial Gd$_2O_3:Eu^{3+}$luminescent thin films have been grout on Si(III) substrates using ionized Cluster Beam Deposition (ICBD). After the film growing, they were implanted and post annealed to change the crystal structure. The initial growth stage was monitored by using in-situ Reflection High Energy Electron Diffraction (RHEED). The formed crystal structure was identified with X-ray diffraction (XRD) technique and Fourier transform infrared (FT-R) spectroscopy. The electronic states variations were investigated by Near Edge X-ray Absorption Fine Structure (NEXAFS). Photoluminescence (PL), Cathodoluminescence (CL). and Vacuum ultraviolet (VUV) spectrum were used for examining the optical properties. We report the optical property changes depending on crystal structure and the electronic states.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.97.2-97
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• 2000

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.3
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• pp.258-263
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• 2002

We present a new toed phosphor, $Gd_{2-x-y}Li_xEu_yO_3$ with superior luminescent Properties compared to the commercially available red phosphor $Y_2O_3:Eu^{3+}$. The phosphor, with a diameter of about $2\mu\textrm{m}$, consists of the psedospherical particles in a regular array. The photoluminescence measurements as a function of the laser power and the Eu mole fraction were performed at zoom temperature The luminescence intensity linearly increases as both the laser power and the Eu mole fraction Increase. As for the dependence on cathodoluminescence, the incorporation of Eu and Li ions into $Gd_2O_3$ lattice brings about an increase in luminescent efficiency. The highest emission intensity for the phosphor occurs at the applied voltage of 500 V, its value is larger than that of $Y_2O_3:Eu^{3+}$ powder by 70%.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.261-264
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• 2014

In this study, $Gd_2O_2S:Tb^{3+}$ was used as the component of the intensifying screen, and this study aims at analysis of fluorescent feature depending on the increase of tube voltage using spectrometer. When the released fluorescence was measured according to the increase of tube voltage, blue, green and red was observed, among which, $^5D_4-^7F_5$ which is applicable to green, was strongest. In addition, when the fluorescent of 50 kVp and 120 kVp were compared, 50 kVp was proved to release only 9.56% fluorescence of 120 kVp. In case when tube voltage which is higher than 100 kVp is used for the X-ray using $Gd_2O_2S:Tb^{3+}$ intensifying screen, the amount and strength of the fluorescence reaching the film increase drastically, so attention is demanded to get images of proper concentration.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.46-55
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• 2002

10mo1% Gd$_2$O$_3$ doped CeO$_2$ fine powders were synthesized by the oxalate coprecipitation method. The characteristics and sintering behavior of fine powders were investigated. The oxalate precipitates had the specific surface area of 150$m^2$/g, and appeared to be fine and spherical primary particles with a size of approximately 5.5nm. The decomposition of the precipitates occurred from a temperature around 30$0^{\circ}C$ and it was completed below 40$0^{\circ}C$, resulted in the formation of the oxide. The calcination temperature of the fine powders was suitable at 77$0^{\circ}C$. By introducing fine powders washed with alcohol and ball-milling process after calcination, the sintered body was possible to attain the value of 97% of the theoretical density at low temperature of 130$0^{\circ}C$

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.362-364
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• 2001

The pulsed laser deposition(PLD) technology was used for the deposition of phosphor substance, Gd$_2$O$_3$on commercial glass. An Nd:YAG laser was employed for the deposition (wavelength 266nm, energy up to 100mJ/pu1se, pulse duration is 5ns and repetition rate 10 Hz). With respect to films grown by conventional PLD, this study exhibited the condition at normal temperature. Experiments were done without any reactive gas at a pressure of 10$^{-5}$ ~10$^{-6}$ Torr using second harmonic(λ=532 nm) and fourth harmonic(λ=266 nm) Nd:YAG laser. Analyses of the deposited material grown are performed by EDX, AFM, SEM, PL meseurements.

• Journal of the Korean Society of Radiology
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• v.2 no.3
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• pp.11-18
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• 2008

In this study, the particle properties and luminescence properties of Gd2O3 nano powder with various Eu content were studied. Gd2O3:Eu nano powder was fabricated using special solvent which mixed the alcohol and the distilled water at specific ratio. This solvent by the solution method showed short fabrication time because solution time of Gd and Eu was reduced. From this experiment with Gd2O3:Eu, the particle properties og nano powder phosphor way analysed using SEM (scanning electron microscope) and EDX(Energy Dispersive X-ray). Also the luminescence properties of nano powder was measured using PL(Photoluminescence) and CL (CathodeLuminescence). The size of powder was 30nm~40nm. The magnitude of powder showed the best peak at 620nm. Among 1,3,5wt% of Eu content, the more Eu content was added in powder, the more photons wre generated. Also it shows luminescence efficiency was improved adding 5% of Eu content.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.461-465
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• 2021

A diffusion heat treatment process for YBa₂Cu₃O_7-y bulk superconductor in a Gd₂O₃ powder was attempted. As a result of measuring the critical temperature of the superconducting bulk, there was no change in the superconducting transition temperature as the Gd particles diffused into the YBa₂Cu₃O_7-y lattice, resulting in dense microstructure. As a result of measuring the critical current, the critical current density (J_c) of the superconducting bulk having treated by the Gd thermal diffusion treatment at 0 T increased to 3×10⁴ A/cm² at 0 T, which was higher than that of the superconducting bulk without thermal diffusion treatment. The surface magnetic force of the superconducting bulk with Gd thermal diffusion treatment was observed at the center of the superconducting bulk with the maximum trapped magnetic force (Hmax) of 1.51 kG. This result means that the Gd thermal diffusion treatment contributes to improving the critical current density Jc of YBa₂Cu₃O_7-y, and it is believed that Gd particles migrating into the superconducting bulk through thermal diffusion either fill the surface pores of YBa₂Cu₃O_7-y superconductors or act as a flux pinning center.