Thermodynamics metastable silicon

The doped semiconductor materials can often be considered as well-characterized, diluted solid solutions. Here, the solutes are referred to as point defects, for instance, oxygen vacancies in TiC - phase, denoted as Vq, or boron atoms in silicon, substituting Si at Si sites, Bj etc. See also -> defects in solids, -+ Kroger-Vink notation of defects. The atoms present at interstitial positions are also point defects. Under stable (or metastable) thermodynamic equilibrium in a diluted state, - chemical potentials of point defects can be defined as follows ... 

Solid silicon monosulphide in an amorphous form has been prepared by the condensation of gaseous SiS at high temperatures. Vaporization and vapour pressure data suggest that SiS is metastable, disproportionating into SiS2 and silicon at an appreciable rate above 950 K. SiS appears to be thermodynamically unstable below 1452 K. Vaporization of solid SiS2 yields predominantly SiS and S2 species according to the dissociation process ... 

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