ELECTRON NUCLEAR DOUBLE-RESONANCE AND ELECTRON-STRUCTURE OF BORON IMPURITY CENTERS IN 6H-SIC

The double electron-nuclear resonance spectrum of boron-doped silicon carbide was recorded for the first time. The hyperfine and quadrupole interaction constants were determined for a boron impurity center with a g tensor of axial symmetry. Assuming that the nondegenerate A level was the ground state, the MO LCAO method was used to analyze the quadrupole interaction with the B-11 nucleus. A model of a boron impurity center in the form of a pi-electron radical BC3 with a planar configuration was proposed. This model accounted qualitatively for the characteristic features of the hyperfine interaction with the B-11 nucleus.