• 제목/요약/키워드: Nd-doped

검색결과 115건 처리시간 0.03초

네오디뮴이 첨가된 프라세오디뮴계 ZnO 바리스터의 I-V 특성 (I-V Characteristics of Praseodymium-Based ZnO Varistors Doped with Neodymium)

  • 박춘현;윤한수;남춘우
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.312-316
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    • 1999
  • I-V characteristics of Praseodymium-based ZnO varistor doped with $Nd_2O_3$ in the range 0.0-2.0mol% sintered at 130$0^{\circ}C$ and 135$0^{\circ}C$ were investigated. In the all sides, ZnO varistors sintered at $1300^{\circ}C$ exhibited much better varistor characteristics than that at 135$0^{\circ}C$. All ZnO varistors doped with $Nd_2O_3$ sintered at $1300^{\circ}C$ exhibited good varistor characteristics but particularly ZnO varistor doped with l.Omol% $Nd_2O_3$ exhibited the best characteristics, which the nonlinear is 65.2 and the leakage current is 4.5pA. It is estimated that ZnO varistor doped with l.Omol% $Nd_2O_3$ will begin to be sufficiently used as basic composition to fabricate a good varistor.

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Neodymium doped mixed metal oxide derived from CoAl-layered double hydroxide: Considerable enhancement in visible light photocatalytic activity

  • Khodam, Fatemeh;Amani-Ghadim, Hamid Reza;Aber, Soheil;Amani-Ghadim, Ali Reza;Ahadzadeh, Iraj
    • Journal of Industrial and Engineering Chemistry
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    • 제68권
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    • pp.311-324
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    • 2018
  • Herein,the Neodymium ion ($Nd^{3+}$) doped CoAl-LDH have been successfully prepared via co-precipitation method and was used as a precursor of Nd-doped CoAl-mixed metal oxides (MMO). The photocatalytic activity of doped LDH and MMO was investigated in the degradation of an azo dye, C.I. Acid Red 14, under visible light irradiation. DRS and PL analysis demonstrated decreasing in the band gap energy and recombination of photo-induced charge carriers of Nd-doped LDH and MMO compared with the pristine CoAL-LDH. Due to significant difference in photocatalytic performance. A power law empirical kinetic model was obtained for predicting the photocatalytic degradation efficiency.

리튬이온전지용 양극활물질 LiNi0.83 Co0.11Mn0.06O2의 전기화학적 특성에 미치는 Ce와 Nd 희토류 금속의 단독 혹은 이중 도핑효과 (Effect of Single and Dual Doping of Rare Earth Metal Ce and Nd Elements on Electrochemical Properties of LiNi0.83 Co0.11Mn0.06O2Cathode Lithium-ion Battery Material)

  • 김유영;하종근;조권구
    • 한국분말재료학회지
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    • 제26권1호
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    • pp.49-57
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    • 2019
  • Layered $LiNi_{0.83}Co_{0.11}Mn_{0.06}O_2$ cathode materials single- and dual-doped by the rare-earth elements Ce and Nd are successfully fabricated by using a coprecipitation-assisted solid-phase method. For comparison purposes, non-doping pristine $LiNi_{0.83}Co_{0.11}Mn_{0.06}O_2$ cathode material is also prepared using the same method. The crystal structure, morphology, and electrochemical performances are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) mapping, and electrochemical techniques. The XRD data demonstrates that all prepared samples maintain a typical ${\alpha}-NaFeO_2$-layered structure with the R-3m space group, and that the doped samples with Ce and/or Nd have lower cation mixing than that of pristine samples without doping. The results of SEM and EDS show that doped elements are uniformly distributed in all samples. The electrochemical performances of all doped samples are better than those of pristine samples without doping. In addition, the Ce/Nd dual-doped cathode material shows the best cycling performance and the least capacity loss. At a 10 C-rate, the electrodes of Ce/Nd dual-doped cathode material exhibit good capacity retention of 72.7, 58.5, and 45.2% after 100, 200, and 300 cycles, respectively, compared to those of pristine samples without doping (24.4, 11.1, and 8.0%).

$Nd_24$O_3$가 첨가된 $Pr_6$$O_{11}$계 ZnO 바리스터의 미세구조 및 전기적 성질 (Microstructure and Electrical Properties of $Pr_6$$O_{11}$-Based ZnO Varistors Doped with $Nd_24$O_3$)

  • 남춘우;박춘현;윤한수
    • 한국전기전자재료학회논문지
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    • 제13권3호
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    • pp.206-213
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    • 2000
  • The microstructure and electrical properties of Pr$_{6}$/O sub 11/-Based ZnO varistors with Nd$_2$O$_3$ was doped in the range of 0.0 to 2.0 mol% were investigated. Most of the added Nd$_2$O$_3$were segregated at the nodal points and grain boundaries and were found to form the Nd-rich phase. In addition the bulk intergranular layer at the grain boundaries and nodal points was consisted of Nd-rich phase and Pr-rich phase. the average grain size was decreased in the range of 7.8 to 5.6${\mu}{\textrm}{m}$ with increasing Nd$_{2}$/O sub 3/ additive content. The nonlinearity of ZnO varistors sintered at 130$0^{\circ}C$ was much more excellent than that at 135$0^{\circ}C$ ZnO varistors doped with 1.0mol% Nd$_{2}$/O sub 3/ exhibited the best nonlinearity. which is 65.2 in the nonlinear exponent and 4.5$\mu$A in the leakage current. Consequently. it is estimated that Pr$_{6}$/O sub 11/ -based ZnO varistors doped with 1.0 mol% Nd$_{2}$/O sub 3/ are to be sufficiently used as basic composition to fabricate good varistors in the future.ure.

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Magnetic Properties and Impedance Spectroscopic Studies of Multiferroic Bi1-xNdxFeO3 Materials

  • Thang, Dao Viet;Thao, Du Thi Xuan;Minh, Nguyen Van
    • Journal of Magnetics
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    • 제21권1호
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    • pp.29-34
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    • 2016
  • Nd-doped $BiFeO_3$ materials were synthesized via a sol-gel method. The crystal structure, magnetic properties, and complex impedance spectroscopy of multiferroic $Bi_{1-x}Nd_xFeO_3$ (BNFO) materials were investigated by X-ray diffraction (XRD), Raman scattering, vibrating sample magnetometer (VSM), and complex impedance spectroscopy. Our results show that the lattice crystal constants (a, c) and the ratio c/a of BNFO materials decreased with increasing Nd concentration. All samples exhibited weak ferromagnetism at room temperature, and the magnetization of samples was enhanced by the presence of $Nd^{3+}$ ions. There was an enhancement in the spontaneous magnetization of BFO with increasing Nd concentration, which is attributable to the collapse of the spin cycloid structure.

Nd이 이온주입된 undoped와 Mg-doped GaN의 분광 특성 연구 (Optical Characterization on Undoped and Mg-doped GaN Implanted with Nd)

  • 송종호;이석주
    • 한국진공학회지
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    • 제15권6호
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    • pp.624-629
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    • 2006
  • Nd을 이온주입한 GaN를 이용하여 GaN와 Nd 이온 사이의 에너지 전달과정을 분석하고 Mg을 도핑 하였을 때의 효과를 보았다. Nd의 $^4F_{3/2}{\rightarrow}^4I_{9/2}$ 전이에 대하여 Photoluminescence (PL)와 PL excitation 방법을 이용하여 에너지 전달 경로에 적어도 3가지 이상의 밴드갭 내의 trap이 있음을 확인하였다. Mg이 doping된 GaN : Nd에서는 isoelectronic trap으로 생각되는 특정한 trap의 수가 증가되었음이 관측되었고 이로 인해 전기적으로 여기될 시료의 특성을 보여줄 밴드갭보다 큰 에너지를 이용한 여기 상태의 효율이 더욱 높아짐을 알 수 있었다.

Efficient Second Harmonic Generation of Pulsed Nd-YAG Laser Radiation with Noncritically Phase-Matchable $LiNbO_3$ in Room-Temperature

  • Jong-Soo Lee;Bong-Hoon Kang;Bum Ku Rhee;Chong-Don Kim;Gi-Tae Joo
    • The Korean Journal of Ceramics
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    • 제6권3호
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    • pp.206-208
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    • 2000
  • 0.65 mol% MgO-doped LiNbO$_3$single crystals were grown by CZ method. The obtained single crystals were colorless and transparent. Noncritically phase-matched second harmonic generation (SHG) of 532-nm radiation from 1064-nm in MgO-doped LiNbO$_3$has been investigated by using pulsed Nd:YAG laser. The phase-matching temperature was room temperature. SHG conversion efficiencies were typically achieved higher than 50% at the phase-matching temperature with no photorefractive damage in the region of fundamental power density which was used in this experiment. The thermo-birefringence coefficient and the electro-birefringence coefficient of SHG were calculated from the temperature phase-matching profile with the electric field.

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

  • 서중원;윤석규;이성문;윤대호
    • 한국세라믹학회지
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    • 제39권10호
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    • pp.977-980
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    • 2002
  • Micro-pulling down법을 이용하여 $Nd_2O_3$가 첨가된 crack 등의 결함이 없는 화학양론조성의 $LiNbO_3$ 단결정을 직경 1 mm, 길이 30∼35 mm의 크기로 성장시켰다. Electron probe micro analysis를 이용하여 결정 내에 $Nd_2O_3$가 균일하게 분포되어있음을 확인하였다. 성장된 결정의 $Nd_2O_3$ 첨가에 따른 흡수 band를 관찰하였고 $Nd_2O_3$ 첨가량 변화에 따른 형광특성의 변화를 측정하였다.

ZnO:P 박막의 레이저 어닐링 연구 (Laser annealing on ZnO:P thin films)

  • 장현우;강홍성;김건희;임성훈;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.51-52
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    • 2005
  • Phosphorus doped ZnO thin films on (001) $Al_2O_3$ substrate have been prepared by a pulsed laser deposition (PLD) technique using a Nd:YAG laser. After deposition, phosphorus doped ZnO thin films have been annealed in vacuum, air, nitrogen, and oxygen ambients using pulsed Nd:YAG laser. We report the electrical properties of phosphorus doped ZnO thin films with the variation of the laser annealing conditions for the applications of optoelectronic devices.

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$Nd^{3+}$로 치환된 $Pb(Mg^{1/3}Nb^{2/3})O_3$$PbTiO_3$ 첨가에 따른 유전특성과 PbO 휘발 (Effects of $PbTiO_3$ Addition on Dielectric Properties and Extent of PbO Loss in Nd-Doped $Pb(Mg^{1/3}Nb^{2/3})O_3$ System)

  • 김성열;이응상
    • 한국세라믹학회지
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    • 제30권8호
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    • pp.671-677
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    • 1993
  • Effects of PbTiO3 addition on dielectric properties and extent of PbO loss in Nd-doped Pb(Mg1/3Nb2/3)O3 system were investigated. As the proportion of dopping increased, the phase transition temperature shifted to low region, and the dielectric constant at room temperature decreased rapidly. But as the proportion of PbTiO3 increased, the phase transition temperature shifted to high retion, and the dielectric constant at room temperature increased. The substitution of Nd3+ for Pb2+ decreased the amount of PbO evaporation, therefore the sample sintered well in case of only 1 mole% adding excess PbO.

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