Five new centers with the electron spins S = ½ and 1 and axial symmetry along c-axis were shown, by electron paramagnetic resonance, to arise in SiC after heavy neutron irradiation and following high-temperature annealing at 1500C. The striking feature of all the centers discovered was a strong hyperfine interaction with a great number of equivalent host Si (C) atoms in SiC lattice. It could be assumed that these defects had high-symmetry structure which suggested a high stability and consists in multi-vacancy clusters. In addition, antisite Si (C) atoms could be included. There was a good probability that some of the new centers could be related to famous D1 center.

Multivacancy Clusters in Silicon Carbide. I.V.Ilyin, M.V.Muzafarova, E.N.Mokhov, P.G.Baranov, S.B.Orlinskii, J.Schmidt: Physica B, 2003, 340-342, 128-31