Simulations were made of the line-shapes at 9.8, 14, 20 and 35GHz of a commonly observed S = ½ electron paramagnetic resonance center in polycrystalline chemical vapor deposited material. It was concluded that the electron paramagnetic resonance signal, which was here labelled H1, resulted from an unique defect with a single H atom which was about 0.19nm away from the unpaired electronic spin. Studies were also made, at 14 and 20GHz, of a similar H-related electron paramagnetic resonance center which was labelled H2. However, the H was here some 0.23nm away. It was proposed that, in each case, a H atom had entered a stretched bond at a grain boundary or other extended misfit region. This permitted the C atoms to relax backwards; with one bonding to the H and the other combining with an unpaired electron in its dangling bond. It was suggested that these results were relevant to H activation at grain boundaries in Si.

X.Zhou, G.D.Watkins, K.M.M.Rutledge, R.P.Messmer, S.Chawla: Physical Review B, 1996, 54[11], 7881-90