Local structure of molten LaCl by K-absorption edge XAFS

Okamoto, Yoshihiro  ; Shiwaku, Hideaki   ; Yaita, Tsuyoshi; Narita, Hirokazu; Tanida, Hajime*

The local structure of molten LaCl was investigated by X-ray absorption fine structure(XAFS) of the La K-edge. The nearest La-Cl distance andcoordination number were 2.89 and 7.4 from the curve fitting of the 1st peak in the fourier transform magnitude . The coordination number larger than 6 suggests that the local structure of molten LaCl is not a simple octahedral coordination (LaCl), but 7-fold (LaCl) and/or 8-fold (LaCl) complexes. The 1st La-La distance, of which correlation was observed as a weak 2nd peak in the , was evaluated to be 4.9. It suggests that the distorted corner-sharing connection of the complex species is predominant in the melt, inontrast with molten YCl in which the edge-sharing connection of the 6-fold (YCl) mainly exists.