The identity of the AB1 and NE4 electron paramagnetic resonance spectra in high-pressure high-temperature diamond

2002 ◽  
Vol 14 (50) ◽  
pp. 13751-13760 ◽  
Author(s):  
W Gehlhoff ◽  
R N Pereira
Keyword(s):  
High Pressure ◽  
Electron Paramagnetic Resonance ◽  
High Temperature ◽  
Paramagnetic Resonance ◽  
High Pressure High Temperature ◽  
Electron Paramagnetic

High-Temperature Stable Multi-Defect Clusters in Neutron Irradiated Silicon Carbide: Electron Paramagnetic Resonance Study

2005 ◽  
Vol 483-485 ◽  
pp. 489-492 ◽  
Author(s):  
P.G. Baranov ◽  
Ivan V. Ilyin ◽  
Marina V. Muzafarova ◽  
E.N. Mokhov ◽  
S.G. Konnikov
Keyword(s):  
Silicon Carbide ◽  
Electron Paramagnetic Resonance ◽  
High Temperature ◽  
Electron Paramagnetic Resonance Study ◽  
High Temperature Annealing ◽  
Axially Symmetric ◽  
Paramagnetic Resonance ◽  
Defect Clusters ◽  
Defect Complexes ◽  
Electron Paramagnetic

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.

Identification of Niobium in 4H-SiC by EPR and Ab Initio Studies

2012 ◽  
Vol 717-720 ◽  
pp. 217-220 ◽  
Author(s):  
Nguyen Tien Son ◽  
Viktor Ivády ◽  
Adam Gali ◽  
Andreas Gällström ◽  
Stefano Leone ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
High Temperature ◽  
Ab Initio ◽  
Electron Spin ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Paramagnetic Resonance ◽  
Form Complex ◽  
Electron Paramagnetic ◽  
Neutral Charge State

In unintentionally Nb-doped 4H-SiC grown by high-temperature chemical vapor deposition (HTCVD), an electron paramagnetic resonance (EPR) center with C1h symmetry and an electron spin S=1/2 was observed. The spectrum shows a hyperfine structure consisting of ten equal-intensity hyperfine (hf) lines which is identified as due to the hf interaction between the electron spin and the nuclear spin of 93Nb. An additional hf structure due to the interaction with two equivalent Si neighbors was also observed. Ab initio supercell calculations of Nb in 4H-SiC suggest that Nb may form complex with a C-vacancy (VC) resulting in an asymmetric split-vacancy (ASV) defect, NbSi-VC. Combining results from EPR and supercell calculations, we assign the observed Nb-related EPR center to the hexagonal-hexagonal configuration of the AVS defect in the neutral charge state, (NbSi-VC)0.

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