Electron nuclear interactions in spin-3/2 color centers in silicon carbide: A high-field pulse EPR and ENDOR study

High-frequency pulse electron paramagnetic resonance (EPR) and nuclear double (ENDOR) were used to clarify the electronic structure of color centers with an optically induced high-temperature spin-3/2 alignment in hexagonal 4H-, 6H- rhombic 15R- silicon carbide (SiC) polytypes. The identification is based on resolved ligand hyperfine interactions carbon nearest, next nearest more distant neighbors determination spin state. ground state excited demonstrated have S = 3/2. microscopic model suggested from EPR ENDOR results as follows: a negatively charged vacancy that noncovalently bonded non-paramagnetic neutral vacancy, located adjacent site along SiC symmetry c-axis.