The aggregation and characteristics of radiation-induced defects in lithium fluoride nanocrystals

Diffusion and aggregation of subsurface radiation defects in lithium fluoride nanocrystals

“…In what fol lows, the samples thus obtained will be referred to as pellets. As follows from [9], convenient object for the observation and investigation of surface defects in lith ium fluoride are nanocrystals exposed to ionizing radi ation at temperatures T irr below the temperature T v corresponding to the mobility of vacancies. In all the samples to be studied, radiation defects were created by irradiation with gamma rays from a 60 Co source at liquid nitrogen temperature T irr = 77 K < T v .…”

“…From formulas (8) and (7) for any given temperature T ann , we obtain (9) The time constants τ 3 and τ 2, 3 (and the rates V 3 and V 2, 3 ) can be experimentally determined using the dependences I(t) for and F S2 centers at the second stage of the kinetics.…”

“…Recently, different types of surface defects were revealed in a subsurface layer of crystals and in LiF nanocrystals, their photoluminescence (PL) and pho toluminescence excitation (PLE) spectra were mea sured, and the compositions were determined [9,10]. The main measurements were performed with nanoc rystals, because they are characterized by an increased content of surface defects as compared to crystals of the same volume under identical irradiation condi tions.…”