PNNL

Abstract

Crystallographic analysis of highly disordered phases is often highly challenging as conventional diffraction-based techniques are ill-suited for this analysis. The alternative approach is to perform the analysis in real space by quantitative atomic resolution imaging. In this work we use STEM HAADF and Differential Phase Contrast analysis to study the prototypical disordered phase of ?-Al2O3, which despite decades of research has remined undetermined. ?-Al2O3 represents an important oxide with a broad use in multiple technological applications. Most importantly, it is heavily used in catalytic applications both as catalyst and catalytic support [1]. We present crystallographic analysis approach for ?-Al2O3 and show that the structural complexity arises from highly intertwined spinel nano-domains connected through finite thickness non-spinel faults.