Non-reactive systems silicon alloys on SiC

To sum up, the good wetting observed for pure Si on SiC (0 = 40°) is due to strong interactions established at the interface between Si and SiC. The addition of 

Ni to Si improves wetting and increases the work of adhesion because interfacial interactions between Ni and SiC are stronger than those between Si and SiC (it should be recalled that Wa is proportional to the solid-liquid interaction energy, equation (1.12)). 

J/m2 and should wet SiC surfaces. This prediction is not confirmed by experimental results obtained in the systematic studies performed by Naidich and Nevodnik (1969) and by Nogi and Ogino (1988), which show large non-wetting contact angles for all metals that have a negligible or a weak reactivity with SiC (Table 7.3). The reasons for this disagreement are discussed in the next Section. 

From Rado s study, it can be concluded that the nature of SiC surface changes dramatically at a temperature T which depends on the oxygen partial pressure in the furnace (in Rado s experiments T % 1050°C). At lower temperatures, the SiC surface is oxidised while at higher temperatures it is graphitized. The transition is continuous around T i.e., without an intermediate state of a non-contaminated, 

Graphitization of SiC in a high vacuum is known to occur above 1100°C by preferential evaporation of Si (Muehlhoff et al. 1986)  

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