OPTICAL PROPERTIES AND FORMATION KINETICS OF M+ CENTERS IN NAF

It is shown that the M+ center in NaF has an absorption band at 740 mμ and an emission band at 943 mμ. M+ centers in NaF can be produced by prolonged x irradiation at room temperature, or by irradiation at low temperature followed by annealing to near room temperature. From a study of the production and transformation of the M and M+ centers it is concluded that the formation of an M center is preceded by the intermediate formation of an M+ center. It is suggested that M centers in NaF, as in LiF, are formed through the reaction α+F→M+, followed by electron capture. The kinetics of aggregation to M+ centers in NaF and LiF are also studied in the present work. © 1968 The American Physical Society.