Experimental and theoretical studies were made of the aggregation of F centers, following irradiation and subsequent heating. The samples were irradiated with 2.5keV electrons, under ultra-high vacuum, at 300K for 0.5h. They were then heated at 1.5K/min. The evolution of F centers from single defects to metal colloids was monitored by means of optical extinction spectroscopy. The concentration of F centers was found to decrease monotonically above 360K, and to fall below the limit of detectability at about 450K. The experimental data were compared with the results of a microscopic theory for F and H center interaction and aggregation. This theory predicted that the activation energy for single F center diffusion was about 1.5eV, and revealed the key role that was played by mutual defect attraction in the aggregation kinetics.

F Center Aggregation Kinetics in Low-Energy Electron Irradiated LiF. N.Bouchaala, E.A.Kotomin, V.N.Kuzovkov, M.Reichling: Solid State Communications, 1998, 108[9], 629-33