• Title/Summary/Keyword: ND3

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Research of Nd:LSB microchip laser (Nd:LSB 마이크로 칩 레이저 연구)

  • 장원권;김태훈;유영문
    • Korean Journal of Optics and Photonics
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    • v.13 no.6
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    • pp.554-558
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    • 2002
  • A new laser material, Nd:LSB $(Nd${3}:LaSc_3(BO_3)_4$, lanthanum scandium borate), of microchip type was grown by the Czochralski pulling method, and tested for optical and lasing properties. Nd:LSB, able to be highly doped with $Nd^{3+}$ ions while maintaining good optical, chemical, mechanical properties, was compared to another Nd-type laser material. The absorption and fluorescence spectra, and fluorescence lifetime were measured, and the crystal structure was analyzed. The lasing characteristics were investigated by using Ti:sapphire laser as a pumping light source.

Solvent Extraction of Nd from Chloride Solution with PC88A (염산용액에서 PC88A에 의한 Nd의 용매추출)

  • Lee Gwang-Seop;Lee Jin-Young;Kim Sung-Don;Kim Joon-Soo;Lee Man-Seung
    • Resources Recycling
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    • v.13 no.4
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    • pp.39-45
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    • 2004
  • Solvent extraction experiments of Nd from chloride solution were studied with PC88A. Solvent extraction reaction of Nd with PC88A and the equilibrium constant were evaluated from the extraction experimental data and extraction conditions. Nd$aq^{3+}$ + 1.5 $H_2$$A_2$,org = $NdA_3$,org + 3H/sun $aq^{+}$ , K=0.25 The predicted distribution coefficients of Nd agreed well with the experimental results. The effect of saponification of PC88A on the extraction of Nd and on the change of equilibrium pH was investigated. Saponified PC88A present as a monomer in the organic reaction and enhanced the distribution coefficient of Nd. The initial extraction conditions had a great effect on the equilibrium pH.

A Study of the synthesis and the properties on microwave dielectric material of BaO--$Nd_2O_3$-$TiO_2$and BaO-(Sm, $ND)_2O_3$-$TiO_2$ system (BaO-$Nd_2O_3$-$TiO_2$계 및 BaO-(Sm, $ND)_2O_3$-$TiO_2$계 마이크로파 유전체의 합성 및 제특성에 관한 연구)

  • 이용석;김준수;이병하
    • Electrical & Electronic Materials
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    • v.10 no.8
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    • pp.819-829
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    • 1997
  • The microwave dielectric materials of the BaO-Nd$_2$O$_3$-TiO$_2$and BaO-(Sm, Nd)$_2$O$_3$-TiO$_2$system were synthesized by conventional ceramic processing and sintered 1220 to 140$0^{\circ}C$ for 2 hours respectively. Their crystallization and dielectric properties were examined. In the BaO-Nd$_2$O$_3$-TiO$_2$ and BaO-(Sm, Nd)$_2$O$_3$-TiO$_2$system. Nd$_2$Ti$_2$O$_{7}$ and (Sm, Nd)$_2$Ti$_2$O$_{7}$ were observed as a second phase respectively. The maximum relative dielectric constant were 79,99 for the BaO-Nd$_2$O$_3$-TiO$_2$system and 105.07 for the BaO-(Sm,Nd)$_2$O$_3$-TiO$_2$system and their Q-value were over 2000 at 3GHz.GHz.

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Magnetic Susceptibilities of the Single Crystal Nd3Se4 (단결정 Nd3Se4의 자기감수율)

  • Cha, Jung-Won;Nahm, Kyun;Kim, Chul-Koo
    • Journal of the Korean Magnetics Society
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    • v.17 no.3
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    • pp.114-119
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    • 2007
  • The single crystal $Nd_3Se_4$ with the $bcc-Th_3P_4$ type structure is grown and the temperature dependent magnetic susceptibilities are measured between 4 K and 300 K. The experimental data are compared with the theoretically calculated susceptibilities which depend on the splitting energies of the $Nd^{3+}$ ground state under the crystal field effect. We find that the magnetic susceptibility of the $Nd^{3+}$ ion in $Nd_3Se_4$ is not affected by the crystal field effect. The spontaneous magnetization curve below $T_c\;=\;53\;K$ of $Nd_3Se_4$ corresponds to the Brillouin function of $Nd_3Se_4$ with J=9/2.

Influence of Ga-Addition on the Manetic Properties of $\alpha-Fe$ Based Nd-Fe-B Alloy (Ga 첨가가 $\alpha$-Fe기 Nd-Fe-B 합금의 자기특성에 미치는 영향)

  • 조덕호;이병엽;조용수
    • Journal of the Korean Magnetics Society
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    • v.7 no.1
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    • pp.44-48
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    • 1997
  • The nanocrystalline Nd-Fe-B alloys with low Nd content were prepared by rapid solidification technique. The alloys consist of both$\alpha$-Fe as the main phase and $Nd_2Fe_{14}B_1$ as a secondary phase and have an ultrafine grain structure of about 30 nm. The addition of Ga in $Nd_4Fe_{82}B_{10}Mo_3Cu_1$ alloy increases remanence up to 1.29 T and improves squareness. The nanocrystalline $Nd_5Fe_{81}B_9Mo_3Cu_1Ga_1$ alloy has a volume fraction of $Nd_2Fe_{14}B_1$ phase of around 35% due to the increase of Nd content and shows an improved coercivity. The remanence, coercivity and energy product of optimally annealed nanocrystalline $Nd_5Fe_{81}B_9Mo_3Cu_1Ga_1$ alloy are 1.24 T, 257.4 kA/m (3.23 kOe), and 100.3 kJ/ ㎥ (12.6 MGOe), respectively.

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Separation Characteristics of NdCl3 from LiCl-KCl Eutectic Salt in a Reactive Distillation Process using Li2CO3 or K2CO3 (탄산화물(Li2CO3, K2CO3)을 이용한 반응증류공정에서 LiCl-KCl 공융염 내 NdCl3의 분리특성)

  • Eun, Hee-Chul;Choi, Jung-Hoon;Lee, Tae-Kyo;Cho, In-Hak;Kim, Na-Young;Yu, Jae-Uk;Park, Hwan-Seo;Ahn, Do-Hee
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.3
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    • pp.181-186
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    • 2015
  • It is necessary to develop an effective waste salt treatment technology for the minimization of radioactive waste generation from the pyroprocessing of spent nuclear fuel. For this reason, the separation characteristics of NdCl3 from LiCl-KCl eutectic salt in a reactive distillation process using Li2CO3 or K2CO3 were observed. NdCl3 was converted into oxychloride (NdOCl) or oxide (Nd2O3) in the reaction model between NdCl3 and the carbonates using HSC-Chemistry, and this result was confirmed in the reactive distillation test of the LiCl-KCl-NdCl3 system using the carbonates. Based on these results, the reactive distillation process conditions were determined to separate NdCl3 into an oxide form (Nd2O3) which can be easily fabricated into a final waste form.

Effects of $Nd_2O_3$ and $TiO_2$ Addition on the Microstructures and Microwave Dielectric Properties of $BaO-Nd_2O_3-TiO_2$ System

  • Kim, Tea-Hong;Park, Jung-Rae;Lee, Suk-Jin;Sung, Hee-Kyung;Lee, Sang-Seok;Choy, Tae-Goo
    • ETRI Journal
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    • v.18 no.1
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    • pp.15-27
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    • 1996
  • The effects of $Nd_2O_3$ and $TiO_2$ addition on the microstructures and microwave dielectic properties of $BaO-Nd_2O_3-TiO_2$ system were investigated. $BaNd_2Ti_4O_{12}$ or $BaNd_2Ti_{5}O_{14}$ phases were observed for compositions based on BaO/$Nd_2O_3$ = 1 ratio. The compositions deviated from $BaO/Nd_2O_3=1$ ratio were composed of major phases of $BaNd_2Ti_4O_{12}$ or $BaNd_2Ti_5O_{14}$, and the compound of $Nd_2O_3$ and $TiO_2(Nd_2Ti_2O_7)$ or that of BaO and $TiO_2(BaTi_4O_9)$. The microstructure of ceramic with $BaO{\cdot}Nd_2O_3{\cdot}4TiO_2$ composition varied from spherical grains to needlelike grains with increasing sintering temperature. With increasing $Nd_2O_3$, the optimum sintering temperature with maximum density increased, and the dielectric constant(${\varepsilon}_r$) and quality factor(Q) decreased due to the formation of secondary phases. With increasing $TiO_2$, the optimum sintering temperature and the dielectric constant decreased with increased Q value. And the temperature coefficient of resonant frequency, ${\tau}_f$ shifted toward positive direction. The dielectric ceramics with $BaO/Nd_2O_3=1$ showed Q values of above 2000 and dielectric constants of above 80 at 3GHz.

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Crystal Growth and Photoluminescence Property of Stoichiometric LiNbO3 Single Crystal Fiber by Addition of Nd2O3 (Nd\2O3 첨가에 따른 화학양론조성 LiNbO3 단결정의 성장 및 형광특성)

  • Shur, Joong-Won;Yoon, Seok-Gyu;Lee, Sung-Mun;Yoon, Dae-Ho
    • Journal of the Korean Ceramic Society
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    • v.39 no.10
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    • pp.977-980
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    • 2002
  • Using the micro-pulling down method, $Nd_2O_3$ doped crack-free stoichiometric $LiNbO_3$ single crystals were grown in 1 mm diameter and 30∼35 mm length. The homogeneous distributions of $Nd_2O_3$ concentration were confirmed by the electron probe micro analysis. The absorption and photoluminescence spectra were measured with respect to the $Nd_2O_3$ doping.

Computer Simulation of Enhancement of Coerciviy in Nd-Fe-B/(Nd,Dy)-Fe-B Composite Magnets

  • Kawasaki, Kohei;Yanai, Takeshi;Nakano, Masaki;Fukunaga, Hirotoshi
    • Journal of Magnetics
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    • v.16 no.2
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    • pp.145-149
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    • 2011
  • The coercivity $H_c$ of $Nd_2Fe_{14}B$ magnets and $Nd_2Fe_{14}B/(Nd_{0.7}Dy_{0.3})_2Fe_{14}B$ composite magnets were calculated by computer simulation based on the micromagnetic theory under assumptions that $Nd_2Fe_{14}B$ and $(Nd_{0.7}Dy_{0.3})_2Fe_{14}B$ grains have magnetically deteriorated layers on their surfaces and diffusion of Dy from $(Nd_{0.7}Dy_{0.3})_2Fe_{14}B$ grains to $Nd_2Fe_{14}B$ ones through the contacting boundaries recovers the magnetic anisotropy of the deteriorated layers of $Nd_2Fe_{14}B$ grains. $H_c$ of $Nd_2Fe_{14}B/(Nd_{0.7}Dy_{0.3})_2Fe_{14}B$ composite magnets increased by the diffusion of Dy from $(Nd_{0.7}Dy_{0.3})_2Fe_{14}B$ grains to $Nd_2Fe_{14}B$ ones and the resultant recovery of the anisotropy field of deteriorated layers of $Nd_2Fe_{14}B$ grains. The $H_c$ vs fraction of $(Nd_{0.7}Dy_{0.3})_2Fe_{14}B$ grains curve were convex for the magnets with the degree of alignment between 0.94 and 0.99, which suggests that the above composite magnets have larger $H_c$ values than the alloy-magnets with the same Dy content, and that we can save the consumption of Dy by using these composite magnets.

High Temperature Oxidation Behavior of Nd-doped $UO_2$ (네오듐 고용 이산화우라늄의 고온 산화거동)

  • Lee, Jae-Won;Kang, Sang-Jun;Kim, Young-Hwan;Cho, Kwang-Hun;Park, Guen-IL;Lee, Jung-Won
    • Applied Chemistry for Engineering
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    • v.24 no.3
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    • pp.227-230
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    • 2013
  • The phase change of $(U_{1-x}Nd_x)_3O_8$ powder produced by oxidation of Nd-doped $UO_2$ pellet at $500^{\circ}C$ was investigated by high temperature oxidation heat treatment at $900{\sim}1500^{\circ}C$ under an air atmosphere. The XRD analysis results showed that the formation of $(U_{1-y}Nd_y)O_{2+z}$ phase and $U_3O_8$ phase from metastable $(U,Nd)_3O_8$ phase initiated at a temperature of $1000^{\circ}C$. The relative integrated intensity of $(U_{1-y}Nd_y)O_{2+z}$ phase to $U_3O_8$ phase increased with increasing of the oxidation temperature from 1100 to $1500^{\circ}C$. And also, it was found from the SEM observation that the particle size of $(U_{1-y}Nd_y)O_{2+z}$ phase increased with increasing of the oxidation temperature. However, electrone probe X-ray microanalyzer (EPMA) analysis results showed that Nd contents in $(U_{1-y}Nd_y)O_{2+z}$ phase decreased with increasing of the oxidation temperature. This behavior on the ground of XRD, SEM, and EPMA analysis data could be interpreted in terms of the transportation of U ions from $U_3O_8$ phase into $(U_{1-y}Nd_y)O_{2+z}$ phase through the interface of two phases during high temperature oxidation.