Layers of Ga14N and Ga15N were interdiffused at temperatures of between 770 and 970C, and the resultant diffusion profiles were measured by using secondary-ion mass spectrometry. The temperature dependence (figure 22) of the N self-diffusion coefficient in the hexagonal phase could be described by:

D (cm2/s) = 1.60 x 103 exp[-4.1(eV)/kT]

The associated entropy for self-diffusion was about 10k.

Nitrogen effusion and self-diffusion in Ga14N/Ga15N isotope heterostructures O.Ambacher, F.Freudenberg, R.Dimitrov, H.Angerer, M.Stutzmann: Japanese Journal of Applied Physics - 1, 1998, 37[5A], 2416-21