| Autor: |
Bernard Pieraggi, Michel Millares, Elvire Lelievre |
| Rok vydání: |
1993 |
| Předmět: |
|
| Zdroj: |
Solid State Ionics. :575-580 |
| ISSN: |
0167-2738 |
| DOI: |
10.1016/0167-2738(93)90161-u |
| Popis: |
Phase growth in the Au-In system has been studied by means of diffusion couples for temperatures between 50 and 150°C. On couples involving pure Au and In the following observations have been made: Only four of the seven phases predicted by the phase diagram have been observed: AuIn 2 , AuIn, Au 7 In 3 and a fourth phase that should be Au 4 In. The AuIn 2 layer represents the major part of the reaction zone. The AuIn 2 and Au 7 In 3 layers have respectively an equiaxial and a columnar grain structure; this reveals a difference in their growth process: AuIn 2 growing by bulk diffusion of In and Au 7 In 3 probably by intergranular diffusion of Au. Growth kinetics of both the AuIn 2 layer and the reaction zone are linear in the first stage of reaction. Thus an interfacial reaction is the rate-limiting step at the beginning of growth. Growth of the AuIn 2 compound has been studied between its two adjacent phases, i.e. AuIn and In. Even in this couple with equilibrium concentration at the interfaces, the first stage of growth is controlled by an interfacial reaction. Kinetic laws taking into account both interfacial reaction and diffusion have shown to fit with experimental points. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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