The Absorption Spectra of Samarium Tungstate and of Samarium Molybdate at Low Temperatures

Abstract

As a preliminary to a study of the relation between the fluorescence and the absorption spectra of crystals, we photographed the absorption spectra of single crystals of Sm2(WO4)3 and of Sm2(MoO4)3 at 78°K, 113°K, 169°K, and 298°K. Evidence was found that an activated state 76 cm-1 from the basic state exists in the tungstate. The general patterns of the spectra of the tungstate and of the molybdate are not the same, indicating that the crystals do not belong to the same space group, an inference likely to be made from crystallographic data. There is also evidence for a dissociation, perhaps an incipient dissociation in the lattice, as if the tungstate and especially the molybdate dissociated into the basic and acidic oxides within the single crystal.