Accession Number : AD0603448

Title :   SMALL ANGLE X-RAY SCATTERING BY METASTABLE LIQUID IMMISCIBILITY IN GLASS.

Descriptive Note : Technical rept. no. 4,

Corporate Author : TEM-PRES RESEARCH INC STATE COLLEGE PA

Personal Author(s) : Williams,John A. ; Phillips,Bert ; Rindone,Guy E. ; McKinstry,Herbert A.

Report Date : 10 JUL 1964

Pagination or Media Count : 52

Abstract : Small angle x-ray scattering measurements were made on samples of CaO-MgO-SiO2 glass in which metastable amorphous phase separation had been induced by heat treatment. Glass rods drawn from a melt of composition 30.5% CaO, 8.0% MgO, 61.5% SiO2 (by weight) at 1400C were heat treated for 1, 2, 10, and 15 hours at 825C. X-ray scattering intensities of heat-treated and non-heat-treated samples were measured using an apparatus based on Kratky collimation geometry and equipped with a pulse height analyzer. Particle sizes were calculated from the radii of gyration which were determined from plots of log intensity vs. theta to the 2nd power, according to the method of Guinier. The data show a growth with time of the dispersed spheres from 350A to 1880A in diameter and correspond to the growth rate for diffusion controlled growth of a sphere. Electron micrographs of identical samples prepared concurrently are presented. Inhomogeneity sizes obtained by the two methods are in very good agreement. Results obtained using the Kratky system in conjunction with a pulse height analyzer are compared with those obtained when a slit collimation system and balanced filter monochromatization were used to study the same sample. (Author)

Descriptors :   (*GLASS, PHASE STUDIES), (*X RAY DIFFRACTION, GLASS), SILICATES, NUCLEATION, CRYSTALLIZATION, RODS, HEAT TREATMENT, PARTICLE SIZE, CRYSTAL GROWTH, MEASUREMENT, COLLIMATORS, ELECTRON MICROSCOPY

Distribution Statement : APPROVED FOR PUBLIC RELEASE