FLUORINE COORDINATION ENVIRONMENTS AROUND CATIONS IN MFN-BAF2-EUF3 GLASSES (M=ZN, AL, GA, IN, SC OR HF)

Fluorine coordination environments around cations in MFn-BaF2-EuF3 gla sses (M=Zn, Al Ga, In, Sc or Hf; n=2 for Zn, 3 for Al, Ga, In and Sc a nd 4 for Hf) have been examined by combined techniques of x-ray radial distribution analysis and molecular dynamics simulation. Good agreeme nt was observed between x-ray radial distribution functions and radial distribution functions obtained by molecular dynamics calculation. Th is fact implys that a Busing-lda-Gilbert type potential function emplo yed for molecular dynamics calculation is relevant and that the parame ters used in calculation are reasonable. Fluorine coordination environ ments around cations in MFn-BaF2-EuF3 glasses were determined based on molecular dynamics calculation. For example fluorine coordination num bers of network forming cations, i.e. Zn2+, Al3+, Ga3+, In3+, Sc3+ and Hf4+, in MFn-BaF2-EuF3 glasses are about 6.1, 6.0, 6.1, 7.2, 6.1 and 7.8, respectively. Fluorine coordination numbers of Ba2+ are in the ra nge from 7.7 to 10.0 and those of Eu3+ are in the range from 8.0 to 9. 0.