High-Temperature Stable Multi-Defect Clusters in Neutron Irradiated Silicon Carbide: Electron Paramagnetic Resonance Study
The high-temperature stable defect complexes in 6H-SiC crystals created by heavy neutron irradiation and following high-temperature annealing have been discovered by EPR. After annealing at 1500°C at least five new axially symmetric centers with the electron spin S = 1/2 and S = 1 were shown to arise in 6H-SiC crystals. The striking feature of all discovered centers is a strong hyperfine interaction with a great number (up to twelve) of equivalent host Si (C) atoms. Two models, a four-vacancy complex VSi-3VC, and a split-interstitial antisite (C2)Si or a pair of two antisites (C2)Si-SiC are discussed. There is a good probability that some of new centers could be related to the famous D1 and DII centers. After annealing at 2000°C the dc1-dc4 centers disappeared and a new triplet center labeled as N-V in the form of a silicon vacancy and a nitrogen atom in neighboring carbon substitutional position has been observed. The parameters of this center are similar to that for well-known N-V center in diamond.
Dr. Roberta Nipoti, Antonella Poggi and Andrea Scorzoni
P.G. Baranov et al., "High-Temperature Stable Multi-Defect Clusters in Neutron Irradiated Silicon Carbide: Electron Paramagnetic Resonance Study", Materials Science Forum, Vols. 483-485, pp. 489-492, 2005