PECULIARITIES OF STABLE FRENKEL DEFECT FORMATION IN RBCL CRYSTALS

Low creation efficiency of stable F-H and alpha-I pairs in RbCl is det ermined by the microstructure of H centres (Cl-2(-) molecule is not in teracting with neighbouring anions). The spectrum of F-centre creation has been measured for RbCI : Tl using synchrotron radiation 6-20 eV. At 295 K the creation efficiency is especially high in the regions 14. 5-15.7 and 15.7-17.0 eV where the energy of hot photoelectrons is suff icient for the formation of near-impurity excitations or secondary exc itons, respectively. A new mechanism of F-H pair creation has been rev ealed in RbCl : Ag, The heating of an irradiated crystal up to 210-240 K provides the tunnel recharging of V-K and Ag-0 centres with the cre ation of Frenkel defects. (C) 1998 Elsevier Science B.V. All rights re served.