Electronic absorption spectra of Sm(II) and Yb(II) ions in a LiCl–KCl eutectic melt at 450 °C

We have measured the absorption spectra of Sm(II) and Yb(II) ions in LiCl–KCl eutectic at 450 °C. The UV spectra of Sm(II) and Yb(II) exhibited intense and broad peaks at around ∼260 nm, which is attributable to the 4f–5d transitions. With the aid of the UV–vis spectroscopic method, in-situ identification of spontaneous reduction of trivalent Sm and Yb ions to divalent ions was achieved.