• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.340.1-340.1
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• 2003

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.249-250
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• 2000

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.215.1-215
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• 1999

• 한국자기학회지
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• 제2권3호
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• pp.257-262
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• 1992

DC 마그테트톤 스퍼터링으로 GdFe 광자기기록용 박막을 복합타켓 배열방법에 따라 제작할때 각 원소의 증착속도의 차이로 인한 특성의 변화를 구하였다. 조성은 증착속도가 증가함에 따라 Gd atomic %가 줄어들며 1.0 ${\AA}/s$ 이상의 증착속도에서는 다소 증가하였다가 감소하는 변화를 보였다. 투입전력에 따른 증착속도는 거의 선형적으로 증가하며, Gd chip의 수를 증가시킬수록 스퍼터링 효율이 높아지는 것으로 나타났다. 투입전력이 증가함에 따라 박막의 보자력도 증가하는데, 이는 Fe 결정립의 크기가 커짐에 따른 것으로 해석된다. 이 실험을 위하여 확산방지벽을 제작하여 스퍼터링에 적용하였고, 이는 재현성을 높이는데 효과가 있었다. Kerr angle gauge를 제작하여 ${\theta}_k$를 측정하였고 ${\theta}_k$는 증착속도에 따라 큰 변화가 없음을 알았다.

• 한국세라믹학회지
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• 제37권7호
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• pp.705-712
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• 2000

In this study, the dispersion stability of CeO2 based complex oxide was studied, and density, porosity, and microstructure of green body were investigated using colloid surface chemistry to manufacture the Gd2O3 doped CeO2 solid electrolyte in an aqueous system. To prepare the stable slurry for slip casting, the dispersion stability was examined as a function of pH using ESA(electrokinetic sonic anplitude) analysis. The dynamic mobility of particles was enhanced with anionic and cationic dispersant were added the amount of 0.5wt% respectively, but pH value in slurries didn't move to below 6.0 because of the influence of dopants. This phenomenon also appeared in the CeO2-Y2O3 and CeO2-Sm2O3 systems, so it could be inferred that rare earth dopants such as Gd2O3, Sm2O3 and Y2O3 not only have the similar motion with changing pH in an aqueous system but also can be dissolved in the range of pH 6.0∼6.5. In CeO2-Gd2O3 system, when the anionic dispersant was added the amount of 0.5wt% and pH value in slurries was fixed at 9.5, the green body density was 4.07g/㎤, and the relative density of sintered body was 95.2%. It could be inferred from XRD analysis that Gd3+ substituted into Ce4+ site because there was no free Gd2O3 peak.

• 한국전기전자재료학회논문지
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• 제15권1호
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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$0^{\circ}C$

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.213.2-213
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• 1999

• Bulletin of the Korean Chemical Society
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• 제27권7호
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• pp.1038-1042
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• 2006

A new type of DTPA-bis-amides (L1-L4) and their Gd(III)-complexes of the type $[Gd(L)(H_2O)]{\cdot}nH_2O$ (5: L1; 6: L2; 7: L3; 8: L4) have been prepared and characterized by analytical and spectroscopic techniques. The X-ray crystal structure of 8 has been determined for structural confirmation. The coordination geometry adopts a tricapped trigonal prism geometry with L4 acting as a chelate octadentate and a water molecule in the coordination sphere. Crystals are monoclinic, $P2_1$, a = 14.468(3), b = 19.235(4), c = 13.527(2) $\AA$ $\beta$ = $107.245(3)^{\circ}$, V = 3595.2(11) $\AA^3$, Z = 4, $D_{calc}$ = 1.570. Significant increases in relaxivities are observed with 6 and 7 as compared with that of $Omniscan^{(R)}$, a commercial MR agent: R1 = 12.46 $mM^{-1}\;s^{-1}$, R2 = 8.76 $mM^{-1}\;s^{-1}$ for 6; R1 = 12.77 nm-1 s-1, R2 = 7.60 mM-1 s-1 for 7; R1 = 4.9 $mM^{-1}\;s^{-1}$, R2 = 4.8 $mm^{-1}\;s^{-1}$ for $Omniscan^{(R)}$. In the case of 5, however, both R1 and R2 are found to be lower to show 2.09 $mM^{-1}\;s^{-1}$, and 1.82 $mM^{-1}\;s^{-1}$, respectively.

• 한국전기전자재료학회논문지
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• 제15권3호
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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%.

• 한국세라믹학회지
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• 제52권6호
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• pp.521-526
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• 2015

$Ce_{0.8}Gd_{0.2}O_{1.9}$(GDC20) powder was prepared from a mixture of submicron-sized $CeO_2$ powder and Gd precipitates using ammonium carbonate $((NH_4)_2CO_3)$ as a precipitant. The mixture was calcined at $700^{\circ}C$ for 4 h followed by ball-milling that resulted in the GDC powder with an average particle size of $0.46{\mu}m$. The powder had a very uniform particle size distribution with particle sizes ranging from $0.3{\mu}m$ to $1{\mu}m$. Sintering of undoped GDC samples did not show a relative density of 99.2% until the temperature was increased to $1500^{\circ}C$, whereas GDC samples doped with 5 mol% CoO exhibited a significant densification at lower temperature reaching a relative density of 97.6% at $1100^{\circ}C$ and of 98.8% at $1200^{\circ}C$.