At 500 to 1300C, the measured T diffusion coefficients were much lower than those expected for metals, while the activation energies were much higher. The results could be described by:

D (cm2/s) = 1.09 x 10-2 exp[-54.9(kcal/mol)/RT]

D (cm2/s) = 2.80 x 101 exp[-65.0(kcal/mol)/RT]

D (cm2/s) = 4.04 x 10-4 exp[-34.0(kcal/mol)/RT]

D (cm2/s) = 1.58 x 100 exp[-73.6(kcal/mol)/RT]

D (cm2/s) = 9.04 x 10-1 exp[-48.2(kcal/mol)/RT]

D (cm2/s) = 8.54 x 100 exp[-64.2(kcal/mol)/RT]

for α-SiC monocrystals, β-SiC monocrystals, Al-doped (50ppm) α-SiC monocrystals, vapour-deposited β-SiC, hot-pressed α-SiC (1%Al) and sintered β-SiC (circa 0.4%B).

R.A.Causey, J.D.Fowler, C.Ravanbakht, T.S.Elleman, K.Verghese: Journal of the American Ceramic Society, 1978, 61[5-6], 221-5