ESR Identification of a New N2(-) Defect in X-Ray Irradiated NaN3.

摘要

A relatively weak ESR spectrum is observed in single crystals of NaN3 after X-ray irradiation at 77 K. This spectrum, which has an anisotropic g value and exhibits a resolved 5-line hyperfine structure with components in the ratio 1:2:3:2:1, corresponds to a single unpaired electron interacting symmetrically with two spin-one nuclei, in three inequivalent sites. The spin-Hamiltonian parameters are: g sub x = 2.0054 + or - 0.0005, g sub y = 2.0045 + or - 0.0005, g sub z = 1.9688 + or - 0.0005, Absolute value of A sub X = 4.0 + or - 0.2 G, Absolute value of A sub y = 20.0 + or - 0.2 G, and Absolute value of A sub z = 4.9 + or - 0.2 G, where z (carat) is tilted 66.5 deg from the c-axis, and y (carat) is perpendicular to the c-axis. This spectrum, which is clearly different from that of substitutional N2(-) is attributed to interstitial N2(-).