Influence of an initial chemical state of cation impurities on their diffusion in ionic crystals

Depth profiles of magnesium, fluorine and oxygen impurities was examined in the surface layers of alkali-halide crystals using method of secondary ion mass spectrometry. Samples of potassium bromide, coated with a surface film of magnesium fluoride were subjected to isothermal diffusion annealing in air at various times. It is shown that the diffusion of O ions occurs from the ambient atmosphere besides the diffusion of Mg and F ions during annealing of KBr crystals. Accurate estimation of the diffusion coefficients of cationic impurity Mg requires taking into account the possible interaction of this impurity and oxygen. The effect of an intensive electron beam on diffusion of magnesium impurity in crystals of fluoride of lithium is studied.