Photoemission studies of alkali halides in the photon energy region 10 to 23 eV

Photocopy of typescript.Bibliography: leaves 131-134.viii, 134 leaves illPhotoemission measurements are reported for ten alkali halides. Extension of energy distribution techniques to photon energies 10 - 23 eV has enabled observation of the electronic states of CsF, CsCl, CsBr, CsI, LiCl, NaCl, KCl, NaF, KF and NaBr. Low lying density of states structures are observed in the conduction bands of all the alkali halides studied. The valence bandwidths of these materials are observed, and the initial state energies are placed with respect to the vacuum level. Structure is observed in the valence bands of CsBr, CsI, LiCl, NaCl, and NaBr; the last three show a doublet splitting too large to be interpreted as spin orbit effects. The Cs+5p doublet is clearly observed in all of the cesium halides. Attention is given to the nature of optical transitions in the alkali halides. For most of these materials neither direct nor non-direct transitions can be eliminated as absorption mechanisms. However, evidence is seen that direct transitions are important in NaCl. Other interesting results include evidence of photoemission following dissociation of core exciton states in CsF, CsCl, and possibly KF, and evidence of electron-exciton scattering in KCl