Regensburg 1998 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 6: Poster

DF 6.25: Poster

Donnerstag, 26. März 1998, 09:30–12:30, A

X-ray diffraction studies of the intermediate range order of metaphosphate glasses — •Rainer Kranold, G"unter Walter, and Ulrich Lembke — Department of Physics, Rostock University, Universitätsplatz 3, D-18051 Rostock

Metaphosphate glasses containing the metal ions Me=Li, Na, K, Ag, Mg, Ca, Co, Zn, Sr, Cd, Ba, Pb, Al, La have been studied by X-ray diffraction. Information on the intermediate range structure of the glasses is extracted from the main peak in the structure factors, S(s), possibly occuring prepeaks, scattering effects in the small angle range and the zero-angle scattering intensity. Most of the glasses studied develop a quasi-periodic superstructure in the intermediate range scale indicated by a prepeak in S(s). The constitution of the superstructure is based on different principles governed by the special kind of metal ion present in the glass. A mixed oxide effect was found for ternary metaphosphate glasses of the Na₂O-BaO-P₂O₅ system but does not exist for the Na₂O-K₂O-P₂O₅ system. Small angle scattering effects are observed only in the S(s) functions of the Mg(PO₃)₂ glasses. The features of these scattering effects depend on the cooling conditions of the glass melt, and their appearance is correlated with the crystallization behaviour of the glasses. This work was supported by the BMBF (Grant 03-KR4ROK-1).