OPTICAL-PROPERTIES OF TERBIUM SULFIDE AND SELENIDE SINGLE-CRYSTALS

The terbium ion Tb+3 is the analog of the cerium ion Ce+3-both are cha racterized by an anomalously low f(N)-->4f(N-1)5d transition energy. T he unusual optical properties of cerium sulfide and selenide, which ar e probably determined by this transition, were observed in a previous study. The transmission and refractive-index spectra and the Faraday e ffect in terbium sulfide and selenide are investigated. It is shown th at according to the position of the fundamental absorption edge, terbi um chalcogenides have no anomalies in the rare-earth series. The behav ior of the Faraday effect in Tb2S3 and Tb2Se3 is different from the Fa raday effect in the sulfides and selenides of rare-earth elements at t he beginning of the rare-earth series. (C) 1996 American Institute of Physics.