Electron paramagnetic resonance and dynamic nuclear polarization via the photoexcited triplet states of radiation defects in natural and 29Si isotope enriched silicon

Electron paramagnetic resonance (EPR) of the triplet centers and dynamic 29Si nuclear polarization was studied in irradiated naturally abounded (4.7%) and 29Si isotope enriched (99.3%) silicon crystals. Saturation of the EPR lines of the photoexcited triplet centers with nonequilibrium spin polarization between mS=+1, 0, and -1 sates leads to the nuclear polarization ∼7000 times higher than equilibrium value. It was shown that the observed dynamic nuclear polarization is a result of the ''solid-effect''. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)