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Browsing by Author "Byung-Chun Choi"

Browsing by Author "Byung-Chun Choi"

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  • Alkali Metal Non-Stoichiometric Effects in (K0.5Na0.5)NbO3 Based Piezoelectric Ceramics 
    S. C. Lee; H-G. Yeo; J. H. Cho; Yeon Soo Sung; M-H. Kim; Tae Kwon SONG; S. S. Kim; Byung-Chun Choi; Kyusang Choi (The Korean Physical Society, 2010-01)
    Alkali-metal-excess lead-free 0.93(K0.5Na0.5)(1+x)NbO3-0.07LiNbO3 (KNNL) piezoelectric ceramics were prepared by using a solid state reaction. The contents of both K and Na were simultaneously controlled to 4 mol% excess. ...
  • Annealing Effect of Photoluminescence Intensity on Eu-doped Y2O3 Nanocrystals 
    Jong-Ho Park; Byung Kee Moon; Byung-Chun Choi; Chung-Sik Kim; Dae-Hwang Yoo; Hyo-Jin Seo; Jeong-In Han; Kyong-Soo Hong; Min Gee Kwak; Nam Gwon Back; Sung-Jei Hong (The Korean Physical Society, 2005-09)
    We synthesized Y2O3 : Eu (15, 20, 25 wt%) nanoparticles by using the liquid-phase reaction method and studied their luminescence characteristic according to the amount of doped europium. The particle size and luminescence ...
  • BaY2ZnO5:Eu2+ 형광체의 합성 및 발광특성 연구 
    심규성; 박성욱; 박진영; 정종원; MOON BYUNG KEE; Byung-Chun Choi; Jeong Jung Hyun (The Korean Physical Society, 2012-08)
    Eu 이온을 도핑한 BaY_2ZnO_5 형광체를 고상반응법으로 합성하고,소결온도와 Eu 이온농도에 따른 표면구조와 결정성 그리고 형광특성을조사하였다. 소결온도를 1000 ℃에서 1300 ℃까지변화시키며 실험한 결과 1300℃에서 BaY_2ZnO_5:Eu^2+형광체의 안정된 결정화가 이루어졌음을 확인하였고, Eu 이온농도는 0.0mol%에서 0.8 mol%까지 영역에서는 400 nm부터 700 ...
  • Crystalline-Phase-Dependent Cathodoluminescence of Li-Doped Gd2O3:Eu3+ Thin-Film Phosphors 
    Jeong Jung Hyun; Soung Soo Yi; Byung-Chun Choi; MOON BYUNG KEE; Hyun Kyoung Yang; Jong Seong Bae; Jung-Hwan Kim; Kyoo Sung Shim (The Korean Physical Society, 2006-09)
  • Dependence of the salt in water-in-crude oil emulsion system 
    Jong-Ho Park; K.S. Hong; Byung-Chun Choi; Ho-Soon Yang; Jeong-Bae Kim; Nam Gwon Back (The Korean Physical Society, 2005-09)
    A cylindrical-shape sample cell was prepared to investigate the dependence of salt amounts in a water-in-crude oil emulsion system by measuring the dielectric properties in the frequency range from 10.2 Hz to 107 Hz with ...
  • Dielectric and Ferroelectric Properties of EuxBa1-xTiO3 Fine Ceramics 
    Byung-Chun Choi; 전병억; Eun Ji Kim; Yu Sung Kim; Jin Soo Kim; MOON BYUNG KEE; Jung Hyun Jeong (The Korean Physical Society, 2008-11)
    EuxBa1-xTiO3 (EBT, x = 0.01 ∽ 0.1) fine ceramics were prepared from EBT nanoparticles, where the sol-gel method was employed to substitute Eu homogeneously for Ba in the BaTiO3. With calcining and sintering the EBT ...
  • Dielectric and p-type Characteristics of Li-doped ZnO Thin Films 
    Guojie Li; Byung-Chun Choi (The Korean Physical Society, 2014-07)
    We report the structural, dielectric and electronic properties of Zn1−xLixO (x = 0.1, 0.05, 0.10) thin films prepared on Pt(111)/Ti/SiO2/Si substrates by using pulsed laser deposition (PLD). Xray diffraction (XRD) analyses ...
  • Dielectric and Piezoelectric Properties of Lead-free (1-x)BaTiO_(3-x)BiScO_3 Ceramics 
    J. H. Cho; M. H. Lee; Yeon Soo Sung; M-H. Kim; T. K. Song; KIM SANG SU; Byung-Chun Choi (The Korean Physical Society, 2011-09)
    The structural, dielectric and piezoelectric characteristics of lead-free (1-x)BaTiO_(3-x)BiScO_3 (0≤ x ≤ 0.45) solid solution ceramics synthesized by solid state reaction have been investigated to use at high temperature ...
  • Dielectric Anomaly and Electric Conductivity of Nd-doped and Nd/V Co-doped Bi4Ti3O12 Ferroelectric Ceramics 
    JIN SOO KIM; Byung-Chun Choi; Jeong Jung Hyun; Tae Kwon SONG; KIM SANG SU; Sangbock Cho (The Korean Physical Society, 2009-08)
    Nd-doped Bi4Ti3O12 (BNT) and Nd/V co-doped Bi4Ti3O12 (BNTV) ferroelectric ceramics were prepared by using a solidstate reaction method. The effects of Nd and Nd/V doping on the dielectric behavior and the electrical ...
  • Dielectric Properties and Phase Transitions in Hetero-Valent-Ion-Substituted (Bi0.5Na0.5)TiO3 Ceramics 
    J. H. Cho; S. C. Lee; L. Wang; H-G. Yeo; Yeon Soo Sung; M-H. Kim; Tae Kwon SONG; S. S. Kim; Byung-Chun Choi (The Korean Physical Society, 2010-01)
    Off-valent-cation (W6+/Nb5+/Sc3+)-substituted lead-free piezoelectric (Bi0.5Na0.5)TiO3 (BNT)ceramics with a single rhombohedral symmetry were fabricated by using a solid state reaction method, and the effects of substitution ...
  • Dielectric, Ferroelectric and Electrical Properties of Bi4Ti3O12 Ceramics with Nd/V and Nd/Nb Co-Doping 
    Jeong Jung Hyun; Jin Soo Kim; Byung-Chun Choi; 노영우; Sutae Chung; Sangbock Cho (The Korean Physical Society, 2008-09)
    Bi4Ti3O12 (BIT), (Bi3.2Nd0.8)Ti3O12 (BNT), (Bi3.2Nd0.8)(Ti2.95Nb0.05)O12 (BNTN) and (Bi3.2 Nd0.8)(Ti2.95V0.05)O12 (BNTV) ceramics were prepared by using a solid state reaction method. The effects of Nd/Nb and Nd/V co-doping ...
  • Diffused Phase Transition of Ba1−xEuxTiO3 Ceramics 
    전병억; Byung-Chun Choi; Jeong Jung Hyun; MOON BYUNG KEE (The Korean Physical Society, 2016-06)
    By applying the sol-gel method, we fabricated Ba1−xEuxTiO3 (BET) ceramics as a single peroveskite phase in the composition range of x = 0 0.20. The BET ceramics displayed a ferroelectric phase transition temperature that ...
  • Effect of Er3+ doping in SnO2 semiconductor nanoparticles synthesized by solgel technique 
    Sangaraju Sambasivam; Saes Byul Kim; Jeong Jung Hyun; Byung-Chun Choi; Kwon Taek Lim; Sang Su Kim; Tae Kwon SONG (The Korean Physical Society, 2010-11)
    Pure and Er3þ doped SnO2 semiconductor nanoparticles have been synthesized by solgel technique. The X-ray diffraction patterns show peaks corresponding to tetragonal structure of SnO2. No Er related impurity peaks could ...
  • Effect of Fe Alloying on the Structural, Optical, Electrical and Magnetic Properties of Spray-deposited CuO Thin Films 
    D. Paul Joseph; C. Venkateswaran; S. Sambasivam; Byung-Chun Choi (The Korean Physical Society, 2012-08)
    Pure CuO and CuO:Fe (10%) thin films were spray deposited on glass, silicon and quartz substrates at 500 ℃. XRD patterns confirmed a monoclinic structure with cubic CuFe<sub>2</sub>O<sub>4</sub> impurities. Surface morphology ...
  • Effect of La Doping on the Dielectric and the Ferroelectric Properties of Lead-Free Na1/2Bi1/2TiO3 (NBT) Ferroelectric Ceramics 
    Kim， Jinsoo; Saes Byul Kim; Byung-Chun Choi; Jeong Jung Hyun; Young Woo No; Su Tae Chung; Se Mo Son (The Korean Physical Society, 2009-02)
    To investigate the effect of La-ion doping, we prepared pure Na1/2Bi1/2TiO3 (NBT) and La-doped Na1/2Bi1/2-xLaxTiO3 (NBLT) ceramics by using a solid-state reaction method. Crystallized NBT and NBLT single-phases were confirmed ...
  • Effect of Nd and Nd/Nb Doping on Dielectric, Ferroelectric and Electrical Properties of Bi4Ti3O12 Ceramics 
    Kim， Jinsoo; Yu Sung Kim; Byung-Chun Choi; Jeong Jung Hyun; Su Tae Chung; Sangbock Cho (The Korean Physical Society, 2009-02)
    Nd-doped Bi4Ti3O12 (BNT) and Nd/Nb-doped Bi4Ti3O12 (BNTN) ferroelectric ceramics were prepared by using a solid-state reaction method. The Nd/Nb co-doping decreased the low-frequency dielectric dispersion and electrical ...
  • Effects of Flux Concentration on the Structural and Luminescent Properties of Eu2+-doped SrAl2O4 
    SEO YEON WOO; MOON BYUNG KEE; Byung-Chun Choi; Jeong Jung Hyun; Koo Sung Shim (The Korean Physical Society, 2014-11)
    Eu2+-doped SrAl2O4 phosphors were synthesized using a solid-state reaction method. The structuraland the luminescent properties of the phosphors were investigated by using X-ray diffraction(XRD), field-emission scanning ...
  • Effects of Tungsten Doping on Dielectric and Impedance Spectroscopy of Bismuth-Lanthanum-Titanate (BLT) Ferroelectrics 
    Jeong Jung Hyun; Jin Soo Kim; Byung-Chun Choi; MOON BYUNG KEE; 전병억; Sangbock Cho (The Korean Physical Society, 2008-09)
    Bismuth lanthanum titanate (Bi3.25La0.75Ti3O12, BLT) and W-doped bismuth lanthanum titanate (Bi3:25La0:75Ti2.95W0.05O12, BLTW) were prepared by using a solid state reaction method. The dielectric and the impedance relaxation ...
  • Electric Modulus Scaling Behaviors of the Near Stoichiometric Potassium Lithium Niobate Crystal 
    전병억; Byung-Chun Choi; Chang-Hoon Kim; Kim Hyung Kook; Jong Seong Bae; Jeong Jung Hyun; Hwang， Yoon-Hwae (The Korean Physical Society, 2006-12)
    An electric modulus analysis was adapted in the low-frequency range from 100 Hz to 1 MHz for the near-stoichiometric potassium lithium niobate (K2.83Li1.84Nb5.33O15.66, KLN43) crystal. KLN43 displayed relaxor-like dielectric ...
  • Electrical Properties of Lead Free (1-x)(Na0.5K0.5) NbO3-xLiNbO3 Piezoelectric Ceramics 
    Park Jong-Ho; Hui-Jin Park; Byung-Chun Choi (Materials Research Society Of Korea, 2016-12)
    This work focuses on the electrical conduction mechanism in a lead free (Na0.5K0.5NbO3 ; NKN) ceramics system with LiNbO3 content of approximately critical concentration x ≥ 0.2. Lead free (1-x)(Na0.5K0.5)NbO3 - x(LiNbO3), ...

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