Group III acceptors with shallow and deep levels in silicon carbide: ESR and ENDOR studies

Results of investigations of Group III acceptors (B, Al, and Ga) in crystals of silicon carbide using the most informative electron spin resonance and electron nuclear double resonance methods are presented. Structural models of the acceptors with shallow and deep levels are considered. In addition to the data obtained earlier, studies using high-frequency magnetic resonance were obtained, which allowed revealing orthorhombic deviations from the axial symmetry for the deep acceptors; theoretical analysis explains experimentally found shifts of $g$ factors for the deep acceptors arising due to the orthorhombic deviations, which appear probably due to the Jahn–Teller effect.