X-Ray Detection of Crystalline Particles in Amorphous Solids
It is relatively common to refer to glass samples as “completely amorphous” when the correct term should be “X-ray amorphous” meaning that crystalline particles are not detectable by X-ray diffraction. The threshold detection limit of crystalline material in a glass is dependent on several variables including the particle size, molecular weight of the glass, and the diffraction efficiency of the crystalline particle. Several powders, including Al2O3, ZrO2, ZrSiO4, quartz (SiO2), SiC, CeO2 and Si3N4, were mixed (via milling) with commercial glass frits ranging from 0.1 to 3.0 volume percent (v/o) and then measured with powder X-ray diffraction. The particle size and density of the crystalline powders was varied while keeping the volume fraction similar. The results show that the average atomic number of the glass frit contributes to X-ray scattering significantly increasing the detection threshold for crystalline particles.
Thesis completed in partial fulfillment of the requirements for the Alfred University Honors Program.
Honors thesis, X-rays, Crystals, Materials science