• Title/Summary/Keyword: $KNi_2F_4$

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A Study of the Cubic Field Splitting Parameter 10Dq by Means of One-Center Expansion of Complex MO (착물 분자궤도함수의 일점 전개에 의한 입방결정장 분열 파라미터 10Dq의 고찰)

  • Hojing Kim;Sangyoub Lee
    • Journal of the Korean Chemical Society
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    • v.22 no.2
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    • pp.67-77
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    • 1978
  • MO's of a complex are expanded in terms of the set of Shull-Lowdin functions based on a single point, the nucleus of central metal ion, and the result was interpreted from the viewpoint of perturbation theory. We find that even in the case of $[NiF_6]^{4-}$, which has relatively small covalency, excited configurations with high orbital angular momentum are considerably mixed into $e_g$ and $t_{2g}$, orbitals of central metal ion, and that the distortions in these orbitals differ from each other. Therefore it is concluded that the energy difference between $e^*_g$ and $t^*_{2g}$, orbitals evaluated in the MO scheme has little meaning of the unique parameter 10Dq in the crystal field theory, and that such a unique parameter cannot be defined in a rigorous sense in the MO scheme.

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Structural and electrochemical characterization of K2NiF4 type layered perovskite as cathode for SOFCs (K2NiF4 type 층상 페롭스카이트 구조 La(Ca)2Ni(Cu)O4-δ의 SOFC 양극 특성 및 결정구조 평가)

  • Myung, Jae-ha;Hong, Youn-Woo;Lee, Mi Jai;Jeon, Dae-Woo;Lee, Young-Jin;Hwang, Jonghee;Shin, Tae Ho;Paik, Jong Hoo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.25 no.3
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    • pp.116-120
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    • 2015
  • $La_2NiO_{4+{\delta}}$ based oxides, a mixed electronic-ionic conductors (MIECs) with $K_2NiF_4$ type structure, have been considerably investigated in recent decades as electrode materials for advanced solid oxide fuel cells (SOFCs) due to their high electrical conductivity, and oxidation reduction reaction (ORR). In this study, structure properties of $La(Ca)_2Ni(Cu)O_{4+{\delta}}$ were studied as a potential cathode for intermediate temperature SOFCs (IT-SOFCs).