The spin multiplicity of TV2a was unambiguously re-determined by using a pulsed electron nuclear double resonance technique. The TV2a center was one of the most commonly observed defects in 4H-SiC, and it was identified as belonging to a class of negatively charged Si vacancies by means of continuous-wave electron paramagnetic resonance and the 2-dimensional nutation method of the pulsed electron paramagnetic resonance technique. A model with the spin multiplicity of triplet (S = 1) and a neutral charge state had recently been suggested. The present results clearly showed that TV2a was a quartet spin (S = 3/2) state, and should thus be singly-negatively charged.

Spin Multiplicity and Charge State of a Silicon Vacancy (TV2a) in 4H-SiC Determined by Pulsed ENDOR. N.Mizuochi, S.Yamasaki, H.Takizawa, N.Morishita, T.Ohshima, H.Itoh, T.Umeda, J.Isoya: Physical Review B, 2005, 72[23], 235208 (6pp)