Investigations of two-level tunneling systems in n-irradiated quartz by diffuse x-ray scattering

Abstract Recent observation of the acoustic saturation and of phonon echoes in crystalline quartz after light irradiation with fast neutrons indicates that there are the same low-energy atomic tunnelling systems as in Si02 glass. We report measurements of the diffuse X-ray scattering and of the lattice parameter change from neutron irradiated quartz single crystals studying the strength and symmetry of strain defects and their local correlations. For dose 3 × 1018 n/cm2 the diffuse scattering close to the Bragg peaks together with the lattice parameter change shows that the neutrons create defective regions with a volume change of 29 mean atomic volumes. The distortion field of these regions shows no high symmetry. The radius of the heavily strained region is ∼ 10 A. For higher doses the regions grow a little bit but mainly new defective regions are built. According to the various volume fractions of defective regions at various doses the first strong amorphous halo at about K≈ 1.5 A−1 was detected. Since...