Raman spectroscopic study of rare earth chlorides in alkali chloride eutectic melts

摘要

Raman spectra of rare earth (REE: rare earth elements) trichloride (REE = Y, La, Ce, Pr, Sm, Gd, Dy, or Yb) dissolved in alkali chloride eutectic melts (LiCl-KCl, LiCl-RbCl, and LiCl-CsCl) were measured at 793 K. The spectra showed polarized peaks centered around 240-270 cm~(-1), which were identified as the totally symmetric stretching vibration (ν_1) of the octahedral REECl_6 ~(3-). The ν_1 frequency increased with the polarizing power of the trivalent REE ions. The change in the ν_1 frequency was found to be larger for lighter lanthanides. This was attributable to the distortion of the O_h symmetry of REECl _6 ~(3-).