Low-temperature radiation effects in wide gap materials

Abstract

Ionizing-and particle irradiation plays an important role as a purposeful modification of material substances to improve their functionality and also allows to implement a thorough analysis of the various material intrinsic properties applying a probing regime of irradiation. The present special journal issue is devoted to low-temperature radiation effects with special attention to radiation-induced/modified structural and impurity defects caused by irradiation of wide gap solids, starting from model single crystals up to layered, glassy and hybrid composite materials.To perform the study with the use of many conventional and up to-date experimental methods, these materials were exposed to irradiation with photons (from IR to VUV-XUV spectral region), x and γ rays, fission neutron etc. The energy absorbed by a material during irradiation is only partly used for the excitation of different types of luminescence applied in scintillators, dosimeters and phosphors for lighting, whereas a significant part of the gained energy is transformed non-radiatively into heat or creation/transformation of structural defects. The ratio between radiative and non-radiative channels of energy dissipation channels depends on many factors and determines the prospects of the material application for certain purposes. As the radiation damage limits many of these applications, the elucidation of the mechanisms of structural defect creation and their possible attenuation/suppression in wide gap materials are of increasing importance.One review article and 13 regular research papers cover a broad class of wide gap materials, starting from model single alkali halide crystals, both pure and doped [1,3,9,11] [13]. The comprehensive review of the relaxation of the electronic excitations and luminescence of rutile-structured SiO 2 and GeO2 crystals and their detailed comparison with α-quartz crystals and relevant glasses was given in paper [6]. The advantages and disadvantages of the implementation of the advanced EPR technique with the use of magnetic circular dichroism to different paramagnetic centres in crystals, glasses and glass-ceramics are considered by Rogulis [1].