Intrinsic defects in SiC nanoparticles as studied by pulsed electron paramagnetic resonance

Stoichiometric and nitrogen doped SiC nanopowders have been investigated by multi-approaches EPR methods. The paramagnetic intrinsic defects formed in the nanoparticles were studied by cw EPR, field swept electron spin echo, pulsed electron nuclear double resonance and hyperfine sublevel correlation spectroscopy. We observe weak 29Si and 13C superhyperfine couplings with silicon and carbon atoms in the second coordination sphere and beyond indicating a high delocalization of the electronic wave function of the unpaired electron. Additional coupling with protons from presumably clustered hydrogen atoms have been detected. Although nitrogen has been found to be present in the nanomaterials no related shallow donor state was formed.