C. Hudalla et al., GLASS-FORMATION AND LOCAL-STRUCTURE IN THE TERNARY-SYSTEM P-SE-AL - SOLID-STATE NMR-STUDIES, Journal of non-crystalline solids, 224(1), 1998, pp. 69-79
Glasses in the system phosphorus-selenium-aluminum have been prepared
by ice-water quenching of sealed ampoules. X-ray powder diffraction an
d differential scanning calorimetry (DSC) of samples indicate a limite
d region of glass formation a in the selenium-rich region of the compo
sition diagram. Structural studies using Al-27 and P-31 solid state NM
R reveal that the local environments of both aluminum and phosphorus a
re dominated by selenium, however, multiple environments are observed
for both glass constituents. The presence of aluminum enhances the ten
dency of phosphorus to become four-coordinate, suggesting that both gl
ass formers interact in the network to some extent. On the other hand,
dipolar solid state NMR studies indicate that the P ... Al interactio
ns are generally smaller than expected on the basis of statistically l
inked PSex and AlSex polyhedra. Together with DSC results, these data
favor a structure that is at least partially segregated and/or phase s
eparated. (C) 1998 Elsevier Science B.V.