The diffusion of D was studied in thin films of the hexagonal phase which had been deposited, by radio-frequency magnetron sputtering, onto metallic substrates. The measurements were carried out by studying transients in the D permeation flux, through substrates which were coated with 400nm-thick films of the nitride, at temperatures ranging from 535 to 752K. The D diffusion coefficient ranged from 1.4 x 10-13 to 5.3 x 10-12cm2/s (table 1), and could be characterized by an activation energy of 0.52eV and a pre-exponential factor which was of the order of 10-8cm2/s. Under steady-state conditions, the D concentration in the hexagonal nitride layers was close to 3 x 1021/cm3.

Deuterium Diffusion through Hexagonal Boron Nitride Thin Films R.Checchetto, A.Miotello: Journal of Applied Physics, 2000, 87[1], 110-6

Table 1

Diffusion of D in BN