* Eutectic temperature

* Eutectic temperature

"Proof" of the 0th law

The compositions along the Si-rich liquidus are in equilibrium with pure solid silicon. The 0th Law requires that the two phases must be in equilibrium with the same vapor. This three-way equilibrium is shown diagrammatically in Fig. 8.12.

Fig. 8.12 Three-way equilibrium in the Au/Si system

Using Eq (8.5), the analytic expression of this equilibrium is:

which must hold along the entire Si-rich liquidus. An alternate form of Eq (8.33) is:

The left-hand side of this equation is strictly phase-diagram information (Table 8.3b). The right-hand side involves data on the vapor-pressures of the solid and liquid phases of pure silicon6. The two sides of Eq (8.33a), which come from independent sources, are plotted in Fig. 8.13.

liquid are obtained by extrapolation from values above the melting temperature.

Because the temperatures in Table 8.2 are below the melting temperature of Si, vapor pressures of the

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

Get My Free Ebook

Post a comment