Characterization of the structure and defects in detonation synthesis, ultr
adisperse diamond (UDD) is reported. X-ray and proton nuclear magnetic reso
nance results on UDD powders are interpreted in terms of the different stru
cture of the shell of UDD particles, produced under different conditions. I
n spite of the comparable contents of carbon and nitrogen atoms in the prec
ursor, no (<10 ppb) paramagnetic nitrogen was detected in the UDD grains. (
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