• Title/Summary/Keyword: lanthanide

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Energy Band Schemes of Organic Electroluminescence Devices Using Lanthanide Metal Complexes (란탄계 금속 착화합물을 이용한 유기 전기 발광 소자의 에너지 밴드 구조의 연구)

  • Pyo, S.W.;Lee, J.H.;Lee, H.S.;Lee, S.H.;Kim, Y.K.;Kim, J.S.
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1735-1737
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    • 1999
  • In this study, several lanthanide complexes such as Eu$(TTA)_3$(Phen). Tb$(ACAC)_3$(Cl-Phen) were synthesized and the white-light electroluminescence (EL) characteristics of their thin films were investigated. where the devices having structures of anode/TPD/Tb$(ACAC)_3$(Cl-Phen)/Eu$(TTA)_3$(Phen)/$Alq_3$ or $Bebq_2$/ cathode and the low work function metal alloy such as Li:Al was used as the electron injecting electrode (cathode). Details on the white-light-emitting characteristics of these device structures were explained by the energy band diagrams of various materials used in these structures, where the energy levels of new materials such as ionization potential (IP) and electron affinity (EA) were measured by cyclic voltametric method.

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Effect of Partial Substitution of Magnetic Rare Earths for La on the Structure, Electric Transport And Magnetic Properties of Oxygen Deficient Phase LaSr2MnCrO7-δ

  • Singh, Devinder;Sharma, Sushma;Mahajan, Arun;Singh, Suram;Singh, Rajinder
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1679-1683
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    • 2013
  • Intergrowth perovskite type complex oxides $La_{0.8}Ln_{0.2}Sr_2MnCrO_{7-{\delta}}$ (Ln=La, Nd, Gd, and Dy) have been synthesized by sol-gel method. Rietveld profile analysis shows that the phases crystallize with tetragonal unit cell in the space group I4/mmm. The unit cell parameters a and c decrease with decreasing effective ionic radius of the lanthanide ion. The magnetic studies suggest that the ferromagnetic interactions are dominant due to $Mn^{3+}$-O-$Mn^{4+}$ and $Mn^{3+}$-O-$Cr^{3+}$ double exchange interactions. Both Weiss constant (${\theta}$) and Curie temperature ($T_C$) increase with decreasing ionic radius of lanthanide ion. It was found that the transport mechanism is dominated by Mott's variable range hopping (VRH) model with an increase of Mott localization energy.

PARAMETER STUDY ON PLASMA-POLYMERIZATION OF LANTHANIDE DIPHTHALOCYANINE FILMS FOR ELECTROCHEMICAL DEVICES

  • Kashiwazaki, Naoya;Yamana, Masao
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.739-744
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    • 1996
  • Lanthanide diphthalocyanines have interesting properties on electrochemical and chemical redox reactions. It is however, difficult to use because of thier short device life. Plasma-polymerization attends to improvement thier device life. Yb-diphthalocyanine ($YbPc_2$) polymer film was deposited in a parallel plate electrodes-type RF plasma reactor. $YbPc_2$ was sublimed into the argon plasma, and polymer film was obtained on a substrate. Radio frequency was constant of 13.56MHz. Pressure of argon gas, sublimation rate of $YbPc_2$ and RF power were variable parameters depending on film quality. Surface of polymer films include a lot of sub-micron order lumps. It was indicated that size of lumps depends on polymerization degree controled by parameters. Size of lumps and polymerization degree are increased with RF power. However, by the high RF power over 40W, polymerization degree is decreased with RF power and surface of film is rough. In condition of RF power is high, polymerization will compete with etching of film. We obtained good films for electrochromic display with RF power of 20W, argon gas pressure of 8.0 Pa and sublimationrate of $1.2 \times 10$ mol/min, and good films for gas sensor with RF power of 30W, argon gas pressure of 10.6Pa and sublimation rate of $1.2 \times 10$ mol/min.

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