ANOMALOUS WIDE-ANGLE X-RAY-SCATTERING STUDY OF STRONTIUM SILICATE ANDALUMINOSILICATE GLASSES

Anomalous wide angle X-ray scattering (AWAXS) is used to investigate t he short and medium range order in Sr silicate and Sr aluminosilicate glasses. Strong Sr-Sr correlations at 4 Angstrom are found in the sili cate glass, whereas they are much weaker in the presence of aluminium. The first Sr-O distance and coordination number and further Sr-Sr dis tances in the silicate glass are consistent with edge sharing octahedr a. The Sr-AL correlations cannot be exactly determined, but the role o f charge compensator imposed on the Sr by tetrahedral Al3+ rapidly red uces the order found in the silicate glass.