Metallic bipolaron phase and its re-entrant phenomenon in the Au mixed-valence compounds Cs2Au2X6(X=Cl, I) under high pressure
| Autor: | F. Fukuhara, Hiroshi Kitagawa, Norimichi Kojima, Hiroki Takahashi, Nobuo Môri |
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| Rok vydání: | 1997 |
| Předmět: |
Bipolaron
Structural phase Valence (chemistry) Condensed matter physics Chemistry Mechanical Engineering Metals and Alloys Condensed Matter Physics Electronic Optical and Magnetic Materials Metal Crystallography Mechanics of Materials Electrical resistivity and conductivity Homogeneous visual_art High pressure Materials Chemistry visual_art.visual_art_medium Re entrant |
| Zdroj: | Synthetic Metals. 86:2175-2176 |
| ISSN: | 0379-6779 |
| DOI: | 10.1016/s0379-6779(97)81083-1 |
| Popis: | Cs 2 [Au I X 2 ][Au III X 4 ](X=Cl, Br, I) are three-dimensional halogen-bridged Au mixed-valence compounds having perovskite type structure. These compounds undergo the pressure induced Au valence transition from the Au I,III mixed-valence state to the homogeneous Au II state, which is coupled with a structural phase transition. In the pressure region below the Au valence transition, these compounds show a metallic behavior, which is attributed to a dynamic two-electron exchange between Au I and AU III (i.e. highly mobile bipolarons). In the case of Cs 2 Au 2 I 6 , the electrical resistivity as a function of temperature shows a re-entrant phenomenon of the metallic bipolaron phase in the vicinity of the Au valence transition. |
| Databáze: | OpenAIRE |
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