ELECTRON NUCLEAR DOUBLE-RESONANCE OF INTRINSIC AND IMPURITY CENTERS IN IONIC-CRYSTALS

In the first sections of this review the principles of the determination of defect structures from hyperfine and superhyperfine interactions and the stationary electron nuclear double resonance (ENDOR) method to resolve them as well as the basic ideas of the analysis of ENDOR spectra are briefly described. Recent experimental developments of ENDOR spectroscopy and the application of advanced ENDOR methods such as ENDOR-induced ESR and double-ENDOR are reviewed. In the following sections results on intrinsic defects such as F centers and hole centers in various ionic crystals are described, which have been obtained since the appearance of Seidel and Wolf's review article (Physics of Color Centers, edited by W. B. Fowler, Academic Press, New York, 1968). Results on impurity centers containing atomic hydrogen, transition metal ions, rare earths and chalcogens are discussed from the beginning of ENDOR work in this field. Finally radiation damage defects are briefly discussed which were not dealt with in other sections.