Electrical Conductivity, Liquidus Temperatures and Raman Spectra of YbCl3–KCl–Yb2O3 and YbCl3–KCl–NaCl–Yb2O3 Systems

The electrical conductivity of 0.507KCl–0.493YbCl 3 and 0.5YbCl 3 –0.25KCl–0.25NaCl chloride melts with the ytterbium oxide (Yb 2 O 3 ) additions ranging from 0 to 3.15 mol% was measured depending on both the temperature and concentration of Yb 2 O 3 . The liquidus temperatures of the studied systems containing from 0 to 3.35 mol.% Yb 2 O 3 were determined by DSC method and the electrical conductivity measurements. The Yb 2 O 3 additions increase the liquidus temperatures of the systems under study. The high-temperature Raman spectra of chloride (YbCl 3 –KCl–NaCl) and oxide-chloride (YbCl 3 –KCl–NaCl–Yb 2 O 3 ) melts were recorded. In the oxide-chloride melt an additional band was detected in the region of 460 cm −1 corresponding to stretching-vibrations of the Yb–O bond in [OYb 3 Cl n ] oxychloride associates. There was no evidence of vibrational bands related to ytterbium oxide. Such changes in the Raman spectrum points to the dissociation of ytterbium oxide and modifications to the local structure of the chloride melt.