Electron-Nuclear Double Resonance of F Centers in Lithium Fluoride

In LiF the spin resonance of the F-center electron is partially resolved by its hyperfine interactions with neighboring nuclei. Discrepancies between observed and theoretically predicted values of these interactions are most serious for the lighter alkali halides. This situation motivated a more detailed experimental investigation of the electronic structure of this center using the new double resonance technique. A crystal of LiF was heavily irradiated with 50- kv x rays thereby inducing a high concentration of F centers. (W.D.M.)