Optical and electrical properties of the mixed valence compound Sm3S4

Abstract The electrical conductivity and the optical reflectivity of single crystals of Sm 3 S 4 (Th 3 P 4 structure, a = 8.5198 ± 0.0003 A) have been investigated. The optical constants have been derived by means of a Kramers-Kronig analysis and interpreted with interband transitions from initial Sm 2+ −4ƒ 6 , Sm 3+ −4ƒ 5 and S 2− −3 p 6 states into the crystal field split Sm-5d band. The Coulomb correlation energy for Sm was found to be 4.5–5 eV.