Grin' L. Radiation-induced defects of Li2B4O7:Ln (Ln=Tm, Eu, Ce) single crystals

Object of investigation - Li2B4O7 (TBL) single crystals non-activated and activated Tm3+, Eu3+, Ce3+ ions. Aim of investigation: to determine the nature of radiation-induced defects in TBL activated Tm3+, Eu3+, Ce3+ ions, to study the influence of activation on the thermostimulated luminescence and additional optical absorption of TBL. Methods of investigations: X-ray diffraction method, atomic-emission spectral analysis, optical spectroscopy, photo- and X-ray luminescence, thermostimulated luminescence, scanning electronic microscopy. Theoretical and practical results, novelty : the main types of TSL centers (O-- hole and F+-, F- electron centers), which caused TSL ТBL:Ln (Ln = Tm, Eu, Ce) single crystals in the temperature range 414ё548 K, their energy and kinetic parameters are determined; calculated is the concentration of radiation-induced defects. It is found that selective stimulation of hole (in LTB:Tm) and electron (in LTB:Ce) intrinsic TSL centers is caused by the type of activator centers.Simultaneous stimulation all of the three TSL intrinsic centers in LTB:Eu is connected with the existence of two activator trapping levels in the forbidden gap of the crystal: hole and electron levels. The influence of internal electric biased fields in activated piezoelectric crystals on the increase of the probability of formation of TSL centers is shown. Field of application: radiation physics, dosimetry, the technology of the increase of efficiency lightsum store of the thermodosimeter material.