F- coordination environments around Eu3+ and Er3+ in MFn-BaF2-LnF3 glasses (M = Zn, Al, Ga, Sc, Zr or Hf, n = 2, 3 or 4, Ln = Eu or Er)

The F- coordination environments around Eu3+ and Er3+ in MFn-BaF2-LnF(3) glasses (M = Zn, Al, Ga, Sc, Zr or Hf; n = 2 for Zn, 3 for Al, Ga and Sc and 4 for Zr and Hf; Ln = Eu or Er) were examined by Eu-L-III and Er-L-III EXAFS spectroscopy and by EU3+ emission spectroscopy. The EXAFS analysis revealed that EU3+ and Er3+ each glass system have almost the same F- coordination environments except for a slight difference due to lanthanoid contraction and also that the F- coordination environments around Eu3+ and Er3+ significantly vary with the MFn glass system. The latter result was also confirmed by Eu3+ emission spectra of the respective glass systems. The present study gave experimental evidence for the validity of the use of Eu3+ instead of Er3+ in order to examine the physicochemical environments of Er3+ in fluoride glasses.