Semiconductor Physics, Quantum Electronics & Optoelectronics. 2010. V. 13, N 1. P. 043-050.


Intrinsic defects in nonstoichiometric β-SiC nanoparticles studied by pulsed magnetic resonance methods
D.V. Savchenko1,2, A. Pöppl2, E.N. Kalabukhova1, E.F. Venger1, M.P. Gadzira3, G.G. Gnesin3

1V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 45, prospect Nauky, 03028 Kyiv, Ukraine Phone: +3(0-44)-525-62-97, fax: +3(0-44)-489-17-04; e-mail: katia@i.kiev.ua
2Fakultät für Physik und Geowissenschaften, Universität Leipzig, Linnéstr. 5, D-04103 Leipzig, Germany; tel: +49-341-973-26-08, fax: +49-341-973-26-49, E-mail: poeppl7@physik.uni-leipzig.de
3Institute for Problems of Materials Science, NAS of Ukraine, 3, Krzhyzhanivskogo str., 03142 Kyiv, Ukraine, Phone: +3(0-44)-424-24-71, fax: +3(0-44)-424-21-31, e-mail: dep14@ipms.kiev.ua

Abstract. Nonstoichiometric β-SiC nanoparticles (np-SiC) have been studied by electron paramagnetic resonance (EPR) and pulsed magnetic resonance methods including field swept electron spin echo (FS ESE), pulsed electron nuclear double resonance (ENDOR) and hyperfine sublevel correlation spectroscopy (HYSCORE). Four ESE signals related to the paramagnetic centers labeled D1, D2, D3, D4 with g = 2.0043, g = 2.0029, g = 2.0031, g = 2.0037 were resolved in FS ESE spectrum due to their different spin relaxation times. As deduced from the study of the superhyperfine structure of the D2 defect by FS ESE, pulse ENDOR and HYSCORE methods the dominant paramagnetic center is a carbon vacancy (V C ) localized in β-SiC crystalline phase of the np-SiC. The parameters of the D2 center coincide with those found for the V C in np-SiC obtained by laser pyrolysis method. Three other defects were identified by comparison of their EPR parameters with the microstructure of the np-SiC. The D1 defect was attributed to the V C vacancy located in α-SiC crystalline phase. The D3 defect is identified with the carbon dangling bonds located in the carbon excess phase. The D4 defect was assigned to a threefold-coordinated Si atom bonded with one nitrogen atom, resulting in the formation of the local bonding Si-Si 2 N configuration in α-Si 3 N 4 phase.

Keywords: SiC nanoparticles, EPR, ESE, ENDOR, HYSCORE.

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