SPECTROSCOPIC TECHNIQUES TO INVESTIGATE AGGREGATION AND PRECIPITATION OF CATION IMPURITIES IN ALKALI-HALIDES - APPLICATION TO IMPURITY HARDENING AND IRRADIATION SENSITIVITY - Lopez Dominguez, Fernando Jesus; Agullolopez, F; Calleja, JM; Cusso, F; Jaque, F; Lopez, FJ (Progress In Materials Science, 1986)