Electrolytic coloration and spectral properties of O(2-)- and Mg(2+)-codoped LiF crystals

O(2-)- and Mg(2+)-codoped (OMC) LiF crystals are colored electrolytically at various temperatures and voltages using a pointed cathode and a flat anode. F, F2, F3(+), Mg-perturbed F and Mg-perturbed F2(+) color centers are produced simultaneously in colored OMC LiF crystals. O(2-)-Va(+), O(2-)-Mg(2+), F, F2, F3(+) and Mg-perturbed F2(+) absorption bands are observed simultaneously in absorption spectrum of colored OMC LiF crystals. O(2-)-Va(+), O(2-)-Va(+) complexes, Mg-perturbed F, F2 and F3(+) fluorescence bands are observed in fluorescence spectra of colored OMC LiF crystals. By using Mollwo-Ivey plot and fluorescence spectroscopy, a room-temperature O(2-)-Va(+) absorption band at 225nm is determined. F3(+) fluorescence of colored OMC LiF crystals is dominant as compared with F2 fluorescence with a single excitation of M-band light. Formation and conversion mechanisms of color centers are discussed.