• 제목/요약/키워드: S-doping

검색결과 692건 처리시간 0.069초

Electron Paramagnetic Resonance of the I2-Doped PBMPV Conducting Polymers

  • Lee, C. H.;Lee, Cheol-Eui;J.-I. Jin;S.-J. Chung
    • Journal of Magnetics
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    • 제2권4호
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    • pp.123-125
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    • 1997
  • We have studied a series of I2-doped poly [2-buthoxy-5-methoxy-1, 4-phenylenevinylene] (PBMPV) conducting polymers by means of electron paramagnetic resonance (EPR) measurements. In this work, the EPR linewidth and spin density were obtained from the EPR intensity and studied as a function of the degree of doping.

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체지방 조직 및 초유중에 잔류되어 있는 다이옥신 함유도에 관한 연구 (The Concentrations and TEQ Levels of PCDFs and PCDDs in Human Adipose Tissue and First Breast Milk of Korean)

  • 김연제;이선영;한순영;박귀례;길광섭;양규환;김은경;김명수
    • 분석과학
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    • 제14권6호
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    • pp.504-509
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    • 2001
  • 우리 나라 사람들의 체지방 조직과 초유중에서, 다이옥신의 잔류 농도를 HRGC/HRMS를 이용하여 동위원소희석법으로 측정하였다. 체지방 조직 시료는 서울에 있는 모병원에서 채취하였으며, 체지방 조직에서의 PCDFs의 총농도와 TEQ 농도는 각각 5.812 pg/g, 1.485 pgTEQ/g 이었고, PCDDs의 총농도와 TEQ 농도는 각각 26.648 pg/g, 1.176 pgTEQ/g 이었다. 서울대학 병원으로부터 받은 산모 20명의 초유에 함유된 다이옥신의 잔류농도는 PCDFs의 총 농도가 7.019 pg/mL, TEQ 농도로 환산하면 0.177 pgTEQ/mL 이었고, PCDDs의 총 농도와 TEQ 농도는 각각 14.224 pg/mL, 0.693 pgTEQ/mL이었다. 체지방 조직과 모유에서의 다이옥신 이성질체들의 분포는 PCDDs가 PCDFs보다 상대적으로 높게 나타났으며, 그중 OCDD가 가장 높은 농도로 포함되어 있다.

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리튬이온전지에서 새로운 양극재료를 위한 금속인산화물 (Lithium Transition Metal Phosphate Cathodes for Advanced Lithium Batteries)

  • 정성윤
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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    • pp.26-26
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    • 2003
  • Lithium storage electrodes for rechargeable batteries require mixed electronic-ionic conduction at the particle scale in order to deliver desired energy density and power density characteristics at the device level. Recently, lithium transition metal phosphates of olivine and Nasicon structure type have become of great interest as storage cathodes for rechargeable lithium batteries due to their high energy density, low raw materials cost, environmental friendliness, and safety. However, the transport properties of this family of compounds, and especially the electronic conductivity, have not generally been adequate for practical applications. Recent work in the model olivine LiFePO$_4$, showed that control of cation stoichiometry and aliovalent doping results in electronic conductivity exceeding 10$^{-2}$ S/cm, in contrast to ~10$^{-9}$ S/cm for high purity undoped LiFePO$_4$. The increase in conductivity combined with particle size refinement upon doping allows current rates of >6 A/g to be utilized while retaining a majority of the ion storage capacity. These properties are of much practical interest for high power applications such as hybrid electric vehicles. The defect mechanism controlling electronic conductivity, and understanding of the microscopic mechanism of lithiation and delithiation obtained from combined electrochemical and microanalytical techniques, will be discussed

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Two-dimensional modelling of uniformly doped silicene with aluminium and its electronic properties

  • Chuan, M.W.;Wong, K.L.;Hamzah, A.;Rusli, S.;Alias, N.E.;Lim, C.S.;Tan, M.L.P.
    • Advances in nano research
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    • 제9권2호
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    • pp.105-112
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    • 2020
  • Silicene is a two-dimensional (2D) derivative of silicon (Si) arranged in honeycomb lattice. It is predicted to be compatible with the present fabrication technology. However, its gapless properties (neglecting the spin-orbiting effect) hinders its application as digital switching devices. Thus, a suitable band gap engineering technique is required. In the present work, the band structure and density of states of uniformly doped silicene are obtained using the nearest neighbour tight-binding (NNTB) model. The results show that uniform substitutional doping using aluminium (Al) has successfully induced band gap in silicene. The band structures of the presented model are in good agreement with published results in terms of the valence band and conduction band. The band gap values extracted from the presented models are 0.39 eV and 0.78 eV for uniformly doped silicene with Al at the doping concentration of 12.5% and 25% respectively. The results show that the engineered band gap values are within the range for electronic switching applications. The conclusions of this study envisage that the uniformly doped silicene with Al can be further explored and applied in the future nanoelectronic devices.