No abstract

No abstract

The influence of radiation on the optical properties of quartz crystals has been investigated. Using the methods of IR and Raman spectroscopy, the lattice dynamics associated with a change in the spectral characteristics of a number of the stretching and deformation vibrations of the crystal lattice upon irradiation of samples by gamma quanta and neutrons to high doses has been determined. The regularities of radiative modification of the spectral characteristics of certain fully symmetrical and degenerate modes of the stretching vibrations of hydroxide groups are determined. To elucidate the reasons for the changes in the optical spectra, the latter were compared with the corresponding spectra obtained upon heating of wafers and with the change in the conductivity of crystals caused by irradiation. It is assumed that the changes in the optical spectra and conductivity of irradiated crystals are mainly due to the rearrangement of the quartz structure and to the stimulated migration of impurities. A possible mechanism of the process of conduction in the material is discussed in the framework of the existing models.Introduction. At the present time, one of the most important directions of scientific investigations is the creation of radiatively and thermally resistant optical, radioelectronic, structural, semiconducting, and multilayer structures on the basis of oxidic inorganic materials. Among the materials widely used for these purposes are silicon and aluminum oxides [1][2][3][4].In [1], a schematic diagram of optical transitions in corundum crystals in a wide spectral region of 9-30 eV is given. In [2], it is reported that on irradiation of the Si-SiO 2 structure by gamma quanta to a dose of 10 6 R the concentration of surface defects and the lifetime of charge carriers in the near-surface region of silicon are increased. A study of the mechanism of tunneling in SiO 2 films is carried out in [3]. The characteristic features of electric energy transfer in single-crystal silicon and SiO 2 with adsorbed water are considered in [4]. In [5], the influence of electrons on the absorption spectra of silicon in a field of 3 µm is investigated. With the foregoing taken into account, the present work continues to study the characteristic features of the action of ionizing radiation -gamma quanta and neutrons -on the optical properties of quartz crystals.Experimental Technique. The objects of investigation were crystals of quartz (in one case, the content of uncontrolled metal impurities was 8⋅10 −3 -2⋅10 −2 wt. %, in another -less than 10 −4 wt. %) in the form of polished rectangular wafers measuring 10 × 10 × 1 mm and disks of diameter 16 mm and thickness 1.5 mm. The IR absorption and Raman spectra were registered before and after radiative irradiation of samples on a UR-20 (Japan) and a Spex (USA) spectrometer, respectively, and the electrical parameters were measured on EK6-11 and IPD-1 devices (Russia). A gamma-ray unit and a nuclear reactor at the Institute of Nuclear Physics, Academy of Sciences of the Republic of ...