Acta Phys. -Chim. Sin. ›› 2006, Vol. 22 ›› Issue (05): 616-621.doi: 10.1016/S1872-1508(06)60022-3

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Phase Equilibrium of the ErCl3-CdCl2- HCl-H2O System at 25 ℃ and Characterization of New Compounds

ZHUO Li-Hong;QIAO Zhan-Ping;GUO Ying-Chen;WANG Hui   

  1. Chemistry Department, Nanyang Normal University, Nanyang 473061, P. R. China;Department of Chemistry,Northwest University, Xi'an 710069, P. R. China
  • Received:2005-11-25 Revised:2006-02-06 Published:2006-04-28
  • Contact: QIAO, Zhan-Ping

Abstract: The equilibriumsolubility of the quaternary systemErCl3-CdCl2-HCl-H2O was determined at 298K and the corresponding equilibrium diagram was constructed. The quaternary system is complicated with four equilibrium solid phases CdCl2·H2O, 9CdCl2·2ErCl3·29H2O , CdCl2·7ErCl3·42H2O, and ErCl3·6H2O. The two newcompounds, 9CdCl2· 2ErCl3·29H2O and CdCl2·7ErCl3·42H2O, have not yet been reported in literatures, and have been characterized by XRD, TG-DTG, and fluorescence spectra. Results showed that the two compounds have fluorescence and upconversion fluorescence, and their intensities increase with the ErCl3 ratio increasing in CdCl2. 9CdCl2·2ErCl3· 29H2O loses its crystal water by three steps in the temperature range from 55 to 215℃, while CdCl2·7ErCl3·42H2O loses its crystal water by one step in the temperature range from65 to 188C℃.

Key words: Quaternary system, Phase equilibrium, Cadmium chloride, Erbium chloride, Upconversion fluorescence