• Title/Summary/Keyword: superprotonic conductor

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Phase Transition and ionic Conductivity of Cesium Hydrogen Sulfate-PAN Composites (황산수소 세슘-PAN 복합체의 상전이와 이온 전도성)

  • 최병구;박상희
    • Polymer(Korea)
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    • v.28 no.2
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    • pp.149-153
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    • 2004
  • The cesium hydrogen sulfate (CsHSO$_4$) crystal is a superprotonic conductor above 140$^{\circ}C$ and possesses protonic conductivity three to low orders of magnitude higher than that at room temperature. Recently, the possibility of it as an electrolyte material for fuel cell system draws much attention. However, its plasticity and absorption of humidity place a limitation on its application. In this study, composites consisting of CsHSO$_4$ and polyacrylonitrile were prepared, and their phase transition properties and the ionic conductivities were evaluated. When the content of CsHSO$_4$ was about 80 vol%, a mechanically strong film with the protonic conductivity of 1${\times}$10$\^$-3/ Scm$\^$-1/ were made.

Study on nuclear magnetic resonance of superionic conductor NH4HSeO4 in rotating frame

  • Choi, Jae Hun;Lim, Ae Ran
    • Journal of the Korean Magnetic Resonance Society
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    • v.18 no.1
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    • pp.41-46
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    • 2014
  • In order to obtain information on the structural geometry of $NH_4HSeO_4$ near the phase transition temperature, the spectrum and spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for the ammonium and hydrogen-bond protons were investigated through $^1H$ MAS NMR. $T_{1{\rho}}$ for the hydrogen-bond protons abruptly decreased at high temperature and it is associated with the change in the structural geometry in $O-H{\cdots}O$ bonds. This mobility of the hydrogen-bond protons may be the main reason for the high conductivity.