The production of color centers in crystals subjected to electron irradiation was studied. The dependence of color-center creation upon the temperature and irradiation dose, as well as upon the direction of crystal growth, was studied. The results of absorption, emission and excitation spectra measurements showed that defect formation in the crystals depended strongly upon the conditions of crystal growth and the preparation of the samples. By comparing BaLiF3 with KMgF3 and LiF, it was possible to attribute absorption bands at 260, 420, 632, 386 and 480nm to F, F2, F2+, F3 and F3+ centers, respectively. Theoretical evaluations, of the absorption energies for these defects, supported these conclusions. Room-temperature electron irradiation of crystals grown in the <100> and <111> directions favored the formation of various types of F-aggregate center for each of these 2 cases. In the case of <100> crystals, it was possible to observe the formation of F2+ centers with one absorption band at 632nm and a corresponding emission at 702nm.

Electron Irradiation-Induced Defects in BaLiF3 Crystals. L.Prado, L.Gomes, S.L.Baldochi, S.P.Morato, N.D.Vieira: Journal of Physics - Condensed Matter, 1998, 10[37], 8247-56