• 제목/요약/키워드: $HoMnO_3$

검색결과 310건 처리시간 0.028초

0.9Pb($Mg_{1/3}Nb_{2/3}$)$O_3$-0.1Pb$TiO_3$계 완화형 강유전체에서 MnO$_2$ 첨가에 따른 압전물성의 변화 (Effect of MnO$_2$ addition on the piezoelectric properties in 0.9Pb($Mg_{1/3}Nb_{2/3}$)$O_3$-0.1Pb$TiO_3$relaxor ferroelectrics)

  • 박재환;박재관;김병국;김윤호
    • 한국재료학회지
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    • 제11권6호
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    • pp.498-501
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    • 2001
  • 0.9Pb($Mg_{1/3}Nb_{2/3}$)$O_3$-0.1Pb$TiO_3$계 완화형 강유전체에서 MnO$_2$ 첨가가 압전물성에 미치는 영향을 강유전성이 우세한 온도영역인 -40~3$0^{\circ}C$의 온도범위에 걸쳐 조사하였다. MnO$_2$ 첨가에 의한 효과를 유전특성, 압전특성, 전계유기 변형특성 등의 영역에서 고찰하였다 MnO$_2$ 첨가량이 증가할수록 유전성 및 압전성은 hard piezoelectric의 경향을 나타내었다. 이러한 실험적 고찰로부터 첨가된 Mn은 강유전 도메인 분역을 고정하는 역할을 하는 것으로 제안되었다.

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수열법에 의한 $(Li,Al)MnO_{2}(OH)_{2}$:Co 화합물의 합성 (Hydrothermal synthesis of $(Li,Al)MnO_2(OH)_2$:Co compound)

  • 최종건;황완인;김판채
    • 한국결정성장학회지
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    • 제11권4호
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    • pp.154-159
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    • 2001
  • (Li,Al)$MnO_2(OH)_2$:Co 화합물의 합성르 수열법에 의해 행하였다. 출발원료는 $MnO_2$, LiOH.$H_2$O, $Co_3O_4$, $Al(OH)_3$이 사용되었으며, 단일상의 (Li,Al)$MnO_2(OH)_2$:Co 화합물을 얻을 수 있는 최적의 합성조건은 다음과 같았다. 반응온도 : $200^{\circ}C$ 반응시간 ; 3일간, 반응장치 ; 시이소형, 수열용매 ; 3M-KOH, (Li,Al)$MnO_2(OH)_2$:Co 의 원자비 = 1:2.1:2.5~2:0.5~1. 수열합성된 단사의 (Li,Al)$MnO_2(OH)_2$:Co 화합물은 결정성이 우수하였으며, 청색안료로써 천연 오수에 필적하는 발색효과를 나타내었다. 합성된 (Li,Al)$MnO_2(OH)_2$:Co 화합물의 형태는 육각 판싱이였으며, 입자의 크기는 0.5~1 $\mu\textrm{m}$의 미립자이였다.

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A Study on the Recovery of Li2CO3 from Cathode Active Material NCM(LiNiCoMnO2) of Spent Lithium Ion Batteries

  • Wang, Jei-Pil;Pyo, Jae-Jung;Ahn, Se-Ho;Choi, Dong-Hyeon;Lee, Byeong-Woo;Lee, Dong-Won
    • 한국분말재료학회지
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    • 제25권4호
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    • pp.296-301
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    • 2018
  • In this study, an experiment is performed to recover the Li in $Li_2CO_3$ phase from the cathode active material NMC ($LiNiCoMnO_2$) in waste lithium ion batteries. Firstly, carbonation is performed to convert the LiNiO, LiCoO, and $Li_2MnO_3$ phases within the powder to $Li_2CO_3$ and NiO, CoO, and MnO. The carbonation for phase separation proceeds at a temperature range of $600^{\circ}C{\sim}800^{\circ}C$ in a $CO_2$ gas (300 cc/min) atmosphere. At $600{\sim}700^{\circ}C$, $Li_2CO_3$ and NiO, CoO, and MnO are not completely separated, while Li and other metallic compounds remain. At $800^{\circ}C$, we can confirm that LiNiO, LiCoO, and $Li_2MnO_3$ phases are separated into $Li_2CO_3$ and NiO, CoO, and MnO phases. After completing the phase separation, by using the solubility difference of $Li_2CO_3$ and NiO, CoO, and MnO, we set the ratio of solution (distilled water) to powder after carbonation as 30:1. Subsequently, water leaching is carried out. Then, the $Li_2CO_3$ within the solution melts and concentrates, while NiO, MnO, and CoO phases remain after filtering. Thus, $Li_2CO_3$ can be recovered.

Mn3O4를 첨가한 Al2O3 세라믹스의 소결 및 광학 특성 (Sintering and the Optical Properties of Mn3O4-added Al2O3)

  • 김진호;백승우
    • 한국전기전자재료학회논문지
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    • 제29권9호
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    • pp.539-545
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    • 2016
  • Alumina added with Mn3O4 up to 7.5 cat% of Mn was prepared by conventional ceramic processing, and the sintering behavior and the optical properties of which were studied as functions of Mn content. Densification and grain growth of alumina were enhanced by Mn addition up to 0.75 cat% but was leveled off at higher concentrations. XRD revealed that $Al_2MnO_4$(galaxite) was formed as a second phase in the specimens with more than 0.75 cat% of Mn. Thus it is believed that either the solid solution effect of Mn or the Zener effect of $Al_2MnO_4$ becomes predominant in the sintering of Mn-added $Al_2O_3$ according to the additive concentration. UV-VIS reflectivity(SCI) spectra of Mn-added $Al_2O_3$ consisted of smooth bottoms in 300~550 nm wavelength range and plateaus at wavelengths longer than 650 nm. The reflectivity spectrum continuously moved downward, and the specimen color became darker and thicker with increasing Mn content. The CIELAB color change with respect to standard white was also dependent on the amount of Mn added: ${\Delta}L^*$(D65) negatively increased and ${\Delta}E_{ab}^*$(D65) positively increased with increasing Mn content, probably due to Mn substitution to Al and/or the mixing effect of black $Al_2MnO_4$ as a second phase.

Growth and Properties of Co-doped Ce,Mn:LiTaO3 Single Crystals

  • Gang, Bong-Hoon;Rhee, Bum-Ku;Lim, Ki-Soo;Bae, Sung-Ho;Joo, Gi-Tae
    • 한국세라믹학회지
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    • 제39권8호
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    • pp.711-714
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    • 2002
  • The Ce, Mn: $LiTaO_3$ crystals were grown by Czochralski method in congruent ${\varphi}$3" $LiTaO_3$ single crystal growing conditions. Concentrations of Ce and Mn in melt were respectively 0.1 mole%. As-grown crystals were red, transparent and the grown crystals were tested with oxidation/reduction treatment for clor and other properties. Influence of Ce and Mn dopants on $LiTaO_3$ crystal properties was discussed. And the nonlinear optical properties of the Ce, Mn: $LiTaO_3$ crystal are being studied.

Magnetic Property of BixCa1-xMnO3: Experimental and First Principles Calculation Study

  • Na, Sung-Ho;Kim, Dong-Jin
    • Journal of Magnetics
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    • 제14권1호
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    • pp.1-6
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    • 2009
  • The magnetic properties of ${Bi_x}{Ca_{1-x}}{MnO_3}$ for x = 0.12, 0.13, 0.14, 0.15, and 0.16 were examined by measuring magnetic susceptibility, resistivity and electron magnetic resonance at different temperatures. ${Bi_x}{Ca_{1-x}}{MnO_3}$ showed complicated magnetic structure that varies with temperature and composition, particularly around Bi composition x. 0.15. The aim of this study was to determine how the magnetic and physical properties of ${Bi_x}{Ca_{1-x}}{MnO_3}$ change in this region. In addition, first principles calculations of the magnetic phase of ${Bi_x}{Ca_{1-x}}{MnO_3}$ for x = 0, 0.125, 0.25 were carried out, and the spin state, electric and magnetic characteristics are discussed.

$LiCoO_2/LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ 복합 정극의 특성 연구 (A Study on Electrochemical Characteristics of $LiCoO_2/LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ Mixed Cathode Materials)

  • 김현수;이영호;김성일;문성인;김우성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.318-319
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    • 2005
  • 본 연구에서는 $LiCoO_2/LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ 혼합 정극활물질로 사용하여 전극을 제작하고 성능을 평가하였다. $LiCoO_2/LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$$LiCoO_2$의 혼합비에 따른 충방전 거동 및 임피던스 변화를 측정하였다. 각 조성에서의 초기용량은 160 ~ 170 mAh/g 정도였으며, $LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$의 첨가 비율이 증가함에 따라 비용량이 증가하였으나 고율에서의 방전용량은 낮았다.

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Mn 첨가량 변화에 따른 Tb/Mn이 첨가된 화학양론조성 LiNbO3 단결정의 광학적 특성 (Optical Properties of Stoichiometric Tb/Mn Co-doped LiNbO3 Single Crystals Dependent on Mn Concentration)

  • 이성문;신동익;김근영;백승욱;윤대호
    • 한국세라믹학회지
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    • 제41권1호
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    • pp.92-95
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    • 2004
  • Micro-Pulling Down (${\mu}$-PD) 법을 이용하여 $MnO_2$$Tb_4O_7$를 첨가하여 crack. 열 strain 등의 결함이 없는 화학양론조성의 $LiNbO_3$ 단결정을 c-축으로 직경 1.0mm, 길이 25-30mm의 크기로 성장시켰다. Electron Probe Micro Analysis (EPMA)를 이용하여 결정 내에 $MnO_2$$Tb_4O_7$이 균일하게 분포되어 있음을 확인하였다. 또한 Fourier Transform-Infrared Spectrophotometer (FT-IR)을 사용하여 OH 흡수밴드를 관찰하였고, 성장된 결정의 $MnO_2$$Tb_4O_7$ 첨가에 따른 형광특성의 변화를 측정하였다.