Negatively charged Si vacancy in 4H SiC: A comparison between theory and experiment

We use electron paramagnetic resonance and electron nuclear double resonance to identify the negatively charged Si vacancy in neutron-irradiated 4H SIG. The identification is based on resolved ligand hyperfine interactions with carbon and silicon nearest and next nearest neighbors and on the determination of the spin state, which is S = 3/2. The magnetic resonance parameters of V-Si(-) are almost identical for the polytypes 3 C, 4H. and 6H. The experimental findings are supported by theoretical ligand hyperfine interaction data based on a total-energy calculation using the standard local-density approximation of the density-functional theory.