Journal ArticleDOI
Potassium iodide + silver iodide phase diagram. High ionic conductivity of KAg4I5
J. N. Bradley,P. D. Greene +1 more
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The phase diagram of the KI+AgI system has been redetermined and two intermediate compounds have been identified as discussed by the authors, KAg4I5 and K2AgI3.Abstract:
The phase diagram of the KI+AgI system has been redetermined. Two intermediate compounds have been identified. K2AgI3 is stable up to 130°C. At higher temperatures it undergoes a solid state disproportionation reaction to KAg4I5 and KI. KAg4I5 is stable between its incongruent melting point (253°C) and 38°C. At lower temperatures it disproportionates to β-AgI and K2AgI3. A eutectic between KAg4I5 and KI occurs at a nominal composition of 29.5 mole % KI and 238°C. The compound KAg4I5 has an exceptionally high ionic conductivity for a solid, reaching 0.31 ohm–1 cm–1 at the incongruent melting point. The current is carried by the Ag+ ions. Thermodynamic data derived from e.m.f. measurements indicate that the formation of KAg4I5 from K2AgI3 and AgI is accompanied by an entropy gain, implying an unusually high degree of disorder in KAg4I5.read more
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Solid State Ionics
TL;DR: The main feature of this area of science and emerging technology is the rapid transport of atomic or ionic species within solids, and various phenomena, of both scientific and technological interest, that are related to it as discussed by the authors.
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Superionics: crystal structures and conduction processes
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High-Conductivity Solid Electrolytes: MAg4I5
Boone B Owens,Gary R. Argue +1 more
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Ionic transport in super ionic conductors: a theoretical model
M.J. Rice,W.L. Roth +1 more
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Crystal Structure of the Solid Electrolyte, RbAg4I5.
TL;DR: The crystal structure of the solid electrolyte RbAg4I5 has been determined from single-crystal x-ray diffraction counter data and the occurrence of the two low-temperature phases has been established by x-rays diffraction and optical examination.