Absorption Spectra of the Samarium Ion in Solids. I. Absorption by Large Single Crystals of SmCl3·6H2O

Abstract

The visible and ultraviolet absorption of large single monoclinic crystals of Sm${\mathrm{Cl}}_3$·6${\mathrm{H}}_2$O has been studied at seven temperatures between 15° and 298°K. Measurements of the absorption lines and bands are given as they appear at four of these temperatures. The influence of temperature on the positions of lines and multiplets and on the width and intensity of lines is discussed. All phenomena are explained on the basis of three direct effects of temperature change on the crystal: Lattice contraction and expansion, temperature vibration of the lattice with consequent fluctuations in crystal fields, and Boltzmann distribution of the ions between excited lower levels about 160, 210 and 300 ${\mathrm{cm}}^{-1\mathrm{}}$ above the basic level.