Investigation of structure of luminescence centres in NaCl–Ni crystals

When introduction of nickel activator into a NaCl crystal is performed by thermal diffusion in the near-surface area of the crystal, impurity clusters of various structures exist simultaneously in consequence of aggregate formation. The given paper shows the scope of application of the FLEXAFS method for examination of the spatial structure of impurity clusters in NaCl crystals with nickel impurity concentration of more than 12 ppm. Also, the possibility of investigation of time history of the cluster structure during synchrotron irradiation is demonstrated.