Amorphous content of alpha alumina

Powder diffraction offers an accessible and accurate method to determine the phase abundance in crystalline mixtures. Unfortunately, only the crystalline components of the mixture are directly assessed. In any finely divided solid, due to relaxation and unsatisfied bonds there will exist at least a disordered surface layer that can amount to several percent of the total mass; additional amorphous material may be present. The improved accuracy of the Rietveld method for data analysis has allowed the determination of the non-crystalline component via "spiking" methods using a reference material with known amorphous content. Thus, the US National Institute for Standards and Technology (NIST) seeks to certify the alumina Standard Reference Material (SRM 676b) specific to quantitative analysis with respect to amorphous content and this is the aim of the proposed experiment.