An optically detected magnetic resonance study was made of the luminescence of monocrystals after 2.5MeV in situ electron irradiation in a 4.2K cryostat. Before warming, a complex anisotropic spectrum was observed at 1.6K and was attributed to a single S = 1 defect of C1h symmetry. Its spectral dependence revealed a weak luminescence band that was centered at about 1.16 and which increased in intensity at resonance. This revealed that the band arose directly from the defect. The optically detected magnetic resonance disappeared during isochronal annealing (0.25h) at temperatures of between 110 and 120K. This contrasted with the predominant luminescence band that was produced by electron irradiation and which was centered at about 1. No optically detected magnetic resonance appeared to arise from it, and it disappeared upon annealing at temperatures of between 90 and 100K. That is, before the optically detected magnetic resonance defect annealed out. The production of preferentially aligned optically detected magnetic resonance centers, by irradiation with an oriented beam, proved that they were primary intrinsic defects and strongly suggested that they were close Frenkel pairs on the Te sub-lattice.

B.Ittermann, F.K.Koschnick, W.A.Barry, M.J.Burnard, G.D.Watkins: Materials Science Forum, 1994, 143-147, 423-8