Assessment of disorder in crystalline powders - a review of analytical techniques and their application

The need to be able to measure amorphous contents in crystalline powders is now recognised. In this review, calorimetric and gravimetric methods are r eviewed in a way that should alert workers in the field to the theoretical, and practical considerations which are important to understanding how best to study crystalline samples which contain low levels of amorphous materia l. It is shown that vapour sorption techniques are very powerful as long as serious consideration is given to the choice of environmental conditions a nd the exact experimental methodology. As the amount of published work in t his field grows, it becomes increasingly necessary to describe experimental and data manipulation methods in great detail. (C) 1999 Elsevier Science B .V. All rights reserved.