Electronically induced defect formation in Xe-doped solid Kr Original Research Article

Lattice defect formation induced by excitation of excimer-type molecular centers in the Kr matrix is studied by the luminescence VUV spectroscopy method. The samples are excited by slow electrons. It is established that the trapping of electronic excitations in the regular lattice regions produces the formation of permanent point defects. The experimental data on the “ground state” mechanism of defect formation associated with radiative decay of electronic excitations and some supporting evidence for the existence of an “excited state” mechanism are obtained. The efficiency of the latter mechanism is found to correlate with the lifetime of electronic excitation of the molecular centers. This mechanism is shown to be electronically thermal. A model of defect creation and stabilization in the excited state is proposed which consists in that the molecular center is displaced to a noncentrosymmetric position followed by its reorientation. The model parameters for the center Kr2* are estimated.