UV absorption of thin-film RbAg4I5-RE (Sm, Yb) systems

Abstract

UV-spectra of samples obtained by vacuum deposition of RE (Sm, Yb) thin films onto films of the solid electrolyte RbAg4I5 (300 – 350 K, thickness 100 – 200 nm) exhibit bands of strong absorption with maxima at 4.3 and 5.0 eV. After the deposition of Sm (≈ 5 nm), the ionic conductivity σ of the samples decreases to ≈ 0.9 σ0 and the lattice parameter from 11.24 to 11.15 A. The halfwidth of X-ray reflections increases from 0.5 to 0.80. Further increase of the concentration of Sm in the samples changes the X-ray diffraction pattern. Under such conditions, the absorption in the regions of 4.3 and 5.0 eV further increases; a new single edge of absorption at 3.8 eV appears and σ declines to ≈10−2 σ0. It is supposed that a genetic relation exists between the UV-bands of strong absorption in the highly defective silver-halides of the RbAg4I5-RE system and the electronic transitions 4d10 −4d9 5s in free Ag+ ions.