Exciton and Low‐Energy Interband Structures in SrO and BaO

Optical reflectivity data are given in the energy region 3.5 to 10 eV on freshly cleaved single crystals of SrO and BaO. The main exciton structures are interpreted in terms of two different k-space excitations one at the zone center, the other at the edge X. Also fine structure near the SrO exciton doublet is observed. On a mesure la reflexion optique dans I'intervalle spectral 3,5 a 10 eV de SrO et BaO monocristallins. Les cristaux ont ete clives en vide. Le principales structures excitoniques ont ete interpretees en termes de deux differentes excitations dans l'espace-k, l'une au centre de la zone, l'autre au point X. On a observe aussi line structure fine pres du doublet excitonique du SrO.