• Journal of the Korean institute of surface engineering
• /
• v.45 no.6
• /
• pp.242-247
• /
• 2012

Yb-doped ITO (ITO:Yb) films were deposited on unheated non-alkali glass substrates by magnetron cosputtering using two cathodes (DC, RF) equipped with the ITO and $Yb_2O_3$ target, respectively. The composition of the ITO:Yb films was controlled by adjusting the RF powers from 0 W to 480 W in 120 W steps with the DC power fixed at 70 W. The ITO:Yb films had a higher crystallization temperature ($200^{\circ}C$) than that of the ITO films ($170^{\circ}C$), which was attributed to both larger ionic radius of $Yb^{3+}$ and higher bond enthalpy of $Yb_2O_3$, compared to ITO. This amorphous ITO:Yb film post-annealed at $170^{\circ}C$ showed a resistivity of $5.52{\times}10^{-4}{\Omega}cm$, indicating that a introduction of Yb increased resistivity of the ITO film. However, these amorphous ITO:Yb films showed a high etching rate, fine pattering property, and a very smooth surface morphology above the crystallization temperature of the amorphous ITO films (about $170^{\circ}C$). The transmittance of all films was >80% in the visible region.

• Journal of the Korean Ceramic Society
• /
• v.39 no.8
• /
• pp.795-800
• /
• 2002

Yb:$YCa_4O(BO_3)_3$ (Yb:YCOB) single crystal, in which the concentration of $Yb^{3+}$ ion 20 at%, was grown by the Czocharalski method using an iridium crucible under N2 atmosphere. The optimum growth parameters to get a high quality of single crystals were found to be 1.5∼2 mm/h of pulling rate and 10∼20 rpm of rotation rate. According to the results of spectroscopic properties, absorption edge of Yb:YCOB was 236 nm. Two strong absorption line due to $Yb^{3+}$ ions were observed at 900 and 975 nm. Thermal expansion coefficients of Yb:YCOB crystal along a, b and c crystallographic axes from 320 to 650 K were 12.1${\times}10^{-6}$/K, 5.9${\times}10^{-6}$/K, 12.9${\times}10^{-6}$/K, respectively. Specific heat was 0.162 $cal/g{\cdot}K$ at 330 K.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.4 no.1
• /
• pp.57-62
• /
• 1994

$YbFeCoO_4$ single crystal was grown by floating zone method. The atmospheric condition of the growth was controlled in air and the growth rate was 1~2 mm/hr. After melting the feed rod of the composition of $YbFeCoO_4$, $YbFeCoO_4$ was decomposed to $YbFeCoO_4$ and CoO phase in the initial state of the growth. The liquid composition, however, changed to the direction of the eutectic point along the liquidus line and then stopped at the point in which $YbFeCoO_4$ single crystal could be grown. The growth direction of the crystal was preferred orientation [110], perpendicular to the c-axis in the hexagonal system due to using the polycrystalline seed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2000.11a
• /
• pp.129-132
• /
• 2000

Perdeuterated hexaflouroacetyIacetonato-ytterbium $[Yb(HFA-D)_3]$ complexes were synthesized by the keto-en01 tautomerism reaction of $Yb(HFA-D)_3$ in methanol-$d_4$ in order to reduce the radiationless transition to the ligands. The luminescence properties of $Yb(HFA-D)_3$ complex were measured in the following anhydrous deuterated organic solvents ; Acetone-$d_6$, Methanol -$d_4$, THF-$d_6$, PO$(OHC_3)_3$ and DMSO-$d_6$. The intensity, lifetime and quantum efficiency of the luminescence in DMSO-$d_6$ were superior to those in other deuterated solvents. It was suggested that the anhydrous DMSO-$d_6$ might be the most appropriate solvent for the liquid laser material of $Yb(HFA-D)_3$ complex.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.04a
• /
• pp.49-53
• /
• 1997

In this paper, YbBa$_{2}$Cu$_{3}$O$_{x}$ superconductor was sintered by means of conventional solid reaction and the textured YbBa$_{2}$Cu$_{3}$O$_{x}$ was prepared by the Melted-Condensed Process in which SmBa$_{2}$Cu$_{3}$O$_{x}$ crystal was used as seed crystal to introduce the YbBa$_{2}$Cu$_{3}$O$_{x}$ crystal growth. The texture of YbBa$_{2}$Cu$_{3}$O$_{x}$ was examined by X-ray diffraction, and the fracture of YbBa$_{2}$Cu$_{3}$O$_{x}$ sample was observed by SEM, which proved the sample was well oriented. After oxygen absorption of the textured YbBa$_{2}$Cu$_{3}$O$_{x}$ sample, it's critical temperature was measureed to be 86K.eed to be 86K.

• Korean Journal of Crystallography
• /
• v.11 no.3
• /
• pp.151-156
• /
• 2000

Yb/YAG single crystals were grown from the melt composition of Y/sub 1-x/Yb/sub x/)₃Al/sub 5/O/sub 12/ where x equal to 5, 10, 15, 20, 25, 33, 50, 75 and 100 at % by floating zone method. Optimum growth parameters to get high quality single crystals were 3.5 mm/h of growth rate and 20 rpm of rotation rate under the N₂ atmosphere. After the growth, color of crystals was appeared with pale blue due to the lack of oxygen, but it was disappeared after annealing at 1450℃ for 2 hr. Absorption coefficients were linearly increased depending on the concentration of Yb/sup 3+/ ions. Broad emission band was measured in the range of 1020 to 1050 nm with the peak intensity at 1031 nm and 1051 nm because of ²F/sub 5/2/(1)→²F/sub 7/2/(3) and ²F/sub 5/2/(1)→²F/sub 7/2/(4) transition respectively. When Yb/sup 3+/ ions were substituted with high rates, there were tendency to decrease the measured fluorescent lifetime for Yb ions depending on the concentration of Yb/sup 3+/ ions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.129-132
• /
• 2000

Perdeuterated hexafluoroacetylacetonato -ytterbium [$Yb (HFA -D)$_3$_3$] complexes were synthesized by the koto-enol tautomerism reaction of $Yb(HFA-H)_3$ in methanol-$d_4$, in order to reduce the radiationless transition to the ligands. The luminescence properties of $Yb(HFA-D)_3$ complex were measured in the following anhydrous deuterated organic solvents : Acetone-$d_6$, Methanol-$d_4$, THF-$d_8$, $PO(OC$H_3$)_3$ and DMSO-$d_6$. The intensity, lifetime and quantum efficiency of the luminescence in DMSO-$d_6$ were superior to those in other deuterated solvents. It was suggested that the anhydrous DMSO-d$_{6}$ might be the most appropriate solvent for the liquid laser material of $Yb(HFA-D)_3$ complex.x.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.08a
• /
• pp.246-247
• /
• 2000

Yb$^{3+}$ 이온은 InGaAs LD 및 Ti:sapphire 레이저로 펌핑할 수 있는 940 nm에서의 흡수대를 가지고 있고, 1.03 $mu extrm{m}$의 형광방출 특성을 가지고 있으며, 지금까지 알려진 1 $\mu\textrm{m}$ 파장대의 레이저 활성이온 중에서 가장 적게 열을 발생하는 특성을 가지고 있음이 알려져 최근에는 Yb$^{3+}$ 이온을 첨가한 여러 가지 레이저 매질이 연구되고 있다.[1] 그 중에서도 Yb$^{3+}$ ion doped yttrium aluminum garnet (Yb:YAG) 단결정은 충분하게 넓은 흡수선폭, 좋은 열광학적 특성, 고출력 작동을 하게 하는 stokes shift, 그리고 LD에 의한 펌핑을 가능하게 하는 940 nm 영역에서의 흡수 및 긴 여기시간을 가진 이상적인 매질로 알려져 있다.[2] 이러한 특성으로 인해 Yb:YAG 단결정은 femtosecond 레이저 등 각종 레이저 시스템의 소형화[3]를 가져왔으며, 레이저 결정의 양산 가능성 및 레이저 기기의 소형화에 따르는 시스템의 가격 감소가 가능하므로 Yb:YAG microchip 레이저는 향후 고출력 레이저 기기 산업의 중추가 될 것으로 기대된다. (중략)

• Applied Chemistry for Engineering
• /
• v.26 no.3
• /
• pp.319-325
• /
• 2015

Submicron-sized $CeO_2:Er^{3+}/Yb^{3+}$ upconversion phosphor particles were synthesized by spray pyrolysis, and their luminescent properties were characterized by changing the concentration of $Er^{3+}$ and $Yb^{3+}$. $CeO_2:Er^{3+}/Yb^{3+}$ showed an intense green and red emission due to the $^4S_{3/2}$ or $^2H_{11/2}{\rightarrow}^4I_{15/2}$ and $^4F_{9/2}{\rightarrow}^4I_{15/2}$ transition of $Er^{3+}$ ions, respectively. In terms of the emission intensity, the optimal concentrations of Er and Yb were 1.0 % and 2.0%, respectively, and the concentration quenching was found to occur via the dipole-dipole interaction. Upconversion mechanism was discussed by using the dependency of emission intensities on pumping powers and considering the dominant depletion processes of intermediate energy levels for the red and green emission with changing the $Er^{3+}$ concentration. An energy transfer from $Yb^{3+}$ to $Er^{3+}$ in $CeO_2$ host was mainly involved in ground-state absorption (GSA), and non-radiative relaxation from $^4I_{11/2}$ to $^4I_{13/2}$ of $Er^{3+}$ was accelerated by the $Yb^{3+}$ co-doping. As a result, the $Yb^{3+}$ co-doping led to greatly enhance the upconversion intensity with increasing ratios of the red to green emission. Finally, it is revealed that the upconversion emission is achieved by two photon processes in which the linear decay dominates the depletion of intermediate energy levels for green and red emissions for $CeO_2:Er^{3+}/Yb^{3+}$ phosphor.

• The Korean Journal of Nuclear Medicine
• /
• v.22 no.1
• /
• pp.77-81
• /
• 1988

Tumor localizing properties of $^{67}Ga$ citrate and $^{169}Yb$ citrate were studies with sarcoma 180 bearing mice. To compare precisely the accumulation of $^{67}Ga$ citrate and $^{169}Yb$ citrate in tumor tissue itself, $^{67}Ga$ and l63yb were administered simultaneously as a mixture of same chemical form of citrate. The yield of $^{169}Yb$ labeled citrated and the of radiopharmaceuticals purity was identified more than 90% by chromatography on silica gel plates. $^{67}Ga$ and $^{169}Yb$ were injected into mice and the mice were killed at 3, 24, and 48 hours following intraperitoneal injection of the radiopharmaceuticals. The retention value of $^{67}Ga$ and $^{169}Yb$ in tumor was similar but they differ from each other markedly in normal tissue distribution. $^{169}Yb$ citrate is cleared up from blood more rapidly than $^{67}Ga$ citrate, and a high tumor to blood ratio is achieved shortly after injection.