• ETRI Journal
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• v.23 no.4
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• pp.151-157
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• 2001

Spectroscopic and thermal analysis indicates that tellurite glasses doped with $B_2O_3$ and $GeO_2$ are promising candidate host materials for wide-band erbium doped fiber amplifier (EDFA) with a high 980 nm pump efficiency. In this study, we measured the thermal stabilities and the emission cross-sections for $Er^{3+}:^{4}I_{13/2}\;{\to}\;^{4}I_{15/2}$ transition in this tellurite glass system. We also determined the Judd-Ofelt parameters and calculated the radiative transition rates and the multiphonon relaxation rates in this glass system. The 15 mol% substitution of $B_2O_3$ for $TeO_2$ in the $Er^{3+}-doped\;75TeO_2-20ZnO-5K_2O$ glass raised the multiphonon relaxation rate for $^4I_{11/2}\;{\to}\;^4I_{13/2}$ transition from 4960 $s^{-1}$ to 24700 $s^{-1}$, but shortened the lifetime of the $^4I_{13/2}$ level by 14 % and reduced the emission cross-section for the $^4I_{13/2}\;{\to}\;^4I_{15/2}$ transition by 11%. The 15 mol% $GeO_2$ substitution in the same glass system also reduced the emission cross-section but increased the lifetime by 7%. However, the multiphonon relaxation rate for $^4I_{11/2}{\to}^4I_{13/2}$ transition was raised merely by 1000 $s^{-1}$. Therefore, a mixed substitution of $B_2O_3$ and $GeO_2$ for $TeO_2$ was concluded to be suitable for the 980 nm pump efficiency and the fluorescence efficiency of $^4I_{13/2}{\to}^4I_{15/2}$ transition in $Er^{3+}-doped$ tellurite glasses.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.1 no.1
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• pp.5-16
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• 1991

It was grown Cubic $ZrO_2(10 mol% Y_2O_3)$ single crystals doped with 1 wt% rare earth metal oxides (RE=Ce, Pr, Nd, Eu, Er) by Skull method. It was investigated electrical properties on (111) plane of grown single crystals by Impedance Spectroscopy. It was potted relation between temperature and electrical conductivities and observed the transition at $약300-400^{\circ}$ It was obtained activation energy on the migration of oxygen vacancy between low temperature (before the transition) and high temperature (after the transition till ${\11}500^{\circ}$) and its difference can be seen the activation energy of the formation of oxygen vacancies by break up defect complexes. It was obtained the activation energy according as add yttria and rare earth metal oxides and discussed ionic conduction mechanism. Grown single crystals showed Ce: orange - red, Pr: golden - yellow, Nd: lilac, Eu: light pink, Er: pink due to dopant effect from the light absorption data in the visible range.

• Journal of the Korean Ceramic Society
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• v.34 no.7
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• pp.722-730
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• 1997

The nonstoichiometry (x) of UO2+x and (Er0.06U0.94)O2+x has been in-situ measure against oxygen activity (Po2) at elevated temperatures by a coulometric titration method. From the dependence of the oxygen excess (x) of UO2+x on Po2 at 1000℃, it has been concluded that (2Vo2Oia2Oib)〃〃and (2Vo2Oia2Oib)' clusters are prevailing at low oxygen partial pressure [log(Po2/atm) -10.6] and at high oxygen partial pressure [log(Po2/atm) -10.6], respectively. The nonstoichiometry is found to be reduced with the addition of Er, which is ascribed to the fact that the fixed-valent Er3+ reduces the oxidation capacities of UO2+x. The enthalpy of oxygen incorporation in (Er0.06li0.94)O2+x has been evaluated from the mean valences of U-ion as -180±70 kJ/mole.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.04a
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• pp.102.2-102.2
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• 2000

• Korean Journal of Materials Research
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• v.17 no.4
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• pp.222-226
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• 2007

[ $SiO_2$ ]thin films containing Si-nanocrystals and $Er^{3+}$ were fabricated by the RF-sputtering method. Intense emission of $Er^{3+}$ was observed at 1530 nm region after the annealing of the film at $1050^{circ}C$ for 5 min. Channel waveguides were fabricated using such films for the core. The films containing Si higher than 2.4 at% exhibited the change in stress from compression to tension after annealing, which induced the fatal loss-increase in waveguide. The optical gain might be attained by the Er-doped waveguide with Si lower than 2.4 at% by a visible-light-excitation.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.219-224
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• 1996

노심설계에서 현재 사용되는 일체형 가연성 흡수봉인 Gd, ZrB$_2$ 그리고 Er의 한국표준형 원전 노심 설계에의 타당성을 노심 F$\Delta$H 제어, 저누출 장전모형 설계, 농축도/주기길이 그리고 주기말의 잔존 페널티 등의 측면에서 분석하였다. 초기노심의 경우는 영광 3호기 1주기 장전모형에 동일 연료집합체를 사용한 Gd/ZrB$_2$/Er의 경우와 ZrB$_2$/Er 최적장전모형에 동일 연료집합체를 사용한 경우에 대하여 분석하였다. 평형노심은 Gd/ZrB$_2$/Er 모두 동일한 장전모형을 사용한 18개월 주기길이의 노심에 대하여 동일한 농축도에서의 주기길이차이와 동등 주기길이를 내는데 필요한 농축도 요구량에 대하여 분석하였다. 초기노심 평형노심 모두 F$\Delta$H 제어에는 ZrB$_2$/Er가 Gd보다 유리하였으며, 저누출 장전모형의 설계에도 ZrB$_2$와 Er가 Gd보다 유리하였다. 평형노심에서 동일한 주기길이를 내는데 요구되는 농축도는 ZrB$_2$에 비하여 Er는 0.182 w/o Gd는 0.063 w/o 높게 나타났으며 동일 농축도를 사용할 경우 주기길이는 ZrB$_2$에 비하여 Gd는 165 MWD/MTU 그리고 Er은 575 MWD/MTU가 짧게 나타났다. 따라서, F$\Delta$H 제어와 저누출 장전모형은 설계에는 ZrB$_2$와 Er가 Gd보다 유리하였으나 Er의 경우 주기말에서의 잔존 페널티가 매우 크다는 단점이 있다.

• Nuclear Engineering and Technology
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• v.28 no.2
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• pp.118-128
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• 1996

The lattice parameters of stoichiometric $UO_2$ and $U_{1-y}Er_{y}O_2$ in the range of y=0.01 to y =0.33 were determined with use of X-ray diffraction data. Oxygen potentials have been measured by means of a thermogravimetric method in the range of 1200~$1500^{\circ}C$ and $10^{-14}$ $\leq$ $Po_2$ $\leq$ $10^{-3}$ for pure $UO_2$ and $U_{1-y}Er_{y}O_{2{\pm}x}$ solid solutions with y=0.02, y=0.06 and y=0.20, respectively. Their oxygen partial pressures were maintained by controlling $CO_2$/CO mixture atmosphere, and the $Po_2$ values corresponding to x of $U_{1-y}Er_{y}O_{2{\pm}x}$ solid solutions were measured with an electrolyte oxygen sensor. The lattice parameter decreases linearly with an increase in the erbium content. The change of the lattice parameter can be expressed in a linear equation of y as a($\AA$) =5.4695-0.220y for 0 $\leq$y$\leq$0.33. The experimental coefficient of y -0.220 in $U_{1-y}Er_{y}O_2$ was an intermediate value between the calculated values -0.273 and -0.156 in the case of $U^{5+}$ and $U^{6+}$, respectively. The (equation omitted) has been found to undergo abrupt increase in the range of -360 to -270 kJ/mole for y=0.06 and -320 to -220 H/mole for y=0.20, respectively, in the temperature range of 1200-$1500^{\circ}C$. (equation omitted) increases with erbium content, but the effect of the dopant for x =0.01 is less significant than that for stoichiometry. The oxygen potentials for $UO_2$ and $U_{0.98}Er_{0.02}O_{2+x}$ can be approximately represented by the $U^{5+}$/$U^{4+}$ model but those for y$\geq$ 0.06 in $U_{1-y}Er_{y}O_{2{\pm}x}$ solid solutions cannot be interpreted by the mean uranium valence model.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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• pp.739-745
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• 1998

The objective of this paper is to provide experimental data of Er(rare- earth)doped $SiO_2$thin film made by sputtering methods. The deposition rate of silica glass by sputtering method was 55$\AA$/min. In EDD measurements, the average Er concentration in the deposited film was 0.77(wt%). After annealing at $900^{\circ}C$, the Cl concentration decreased from 3.79(wt%) to 1.52(wt%). The refractive indices of the core $n_1$, cladding $n_2$ were 1.458, 1.558 respectively at 632.8 nm. The refractive index difference between core and cladding, $\Delta$n was 0.1. The refractive index profile of core and cladding interface shows step profile. In the study, $SiO_2$ glass films of Si wafer were successfully doped with active erbium. Therefore, this experimental data will be applicable for fabrications of Er doped planar integrated optical device.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.269.2-269
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• 2002

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.42-43
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• 2002

고상 소결법으로 715iO$_2$＋11$Na_2$O＋10CaO＋3Er$_2$O$_3$＋5Yb$_2$O$_3$(all wt%) 조성의 스퍼터용 유리 타겟을 제조하여, RF 마그네트론 스퍼터에 의해 희토류 원소가 첨가된 광증폭기용 다성분계 sodium calcium silicate 유리박막을 제조하였다. 최적의 공정조건을 얻기 위해 RF-power, 공정압력, 기판온도를 변화시키면서 박막을 제조하여 RF-power 150W, 공정압력 4mtorr, 기판온도 50$0^{\circ}C$, 타겟-기판 거리 6cm에서 타겟의 손상이 심하지 않으면서, 1.4$mu extrm{m}$/h의 최고 증착율을 가지는 양질의 박막을 제조하였다. (중략)