États de surface du sodium dans les directions (100) ET (111)

All Surface Science 91 (1980) 358-364 © North-Holland Publishing Company I~TATS D E S U R F A C E D U S O D I U M D A N S L E S D I R E C T I O N S ( 1 0 0 ) ET ( 1 1 1 ) R. G A R R O N Universit~ d'Aix-Marseille 111, bbcult~ des Sciences et Techniques, Centre de Saint J~r6me, Dipartement d'Emission Electronique, Rue Henri Poincari, F.13397 Marseille Cedex 4, France Received 30 March 1979 The electron states located near the (100) and (111) surfaces of a Na crystal have been investigated. The modifications of the crystalline structure of the surfaces do not change the electronic structure of the levels occupied in the fundamental state. We discuss an eventual intervention of the located states in the variations of the optical conductivity of Na before the threshold of the interband transitions.