CALCULATION OF THE HYPERFINE-INTERACTION TENSORS OF THE P(GA) ANTISITE IN GAP

The tight-binding theory of defects by Hjalmarson et al. [Phys. Rev Le tt. 44, 810 (1980)] is used to calculate the wave function of an elect ron localized near the P(Ga) antisite in GaP. The effect of the defect potential is extended to the nearest-neighbor sites, including the ef fects of lattice relaxation around the antisite phosphorous. From the calculated wave function, the hyperfine interaction of an electron wit h a P or a Ga nucleus near the defect is obtained and compared with el ectron-spin-resonance data and optically detected magnetic-resonance d ata. Good agreement is obtained for antisite phosphorus and nearest-ne ighbor atoms. The effects of lattice relaxation on the defect energy l evel, the wave function, and the hyperfine-interaction constants are d iscussed. The outward relaxation of nearest-neighbor atoms was determi ned to be 21% of the bond length.