The diffusion of 30Si was measured along the c-axis of -phase quartz, at temperatures of between 1400 and 1600C (table 120), by using Rutherford back-scattering spectrometry and the 30Si(p,)31P resonant nuclear reaction. It was found that the diffusivity could be described by:

D(cm2/s) = 106.1 exp[-7.6(eV)/kT]

These values were comparable to the diffusivity of Si in vitreous SiO2. It was suggested that Frenkel pairs were the majority defects, and that diffusion occurred via an interstitial mechanism.

O.Jaoul, F.Béjina, F.Elie, F.Abel: Physical Review Letters, 1995, 74[11], 2038-41

Table 120

Diffusivity of 30Si in -Quartz