Microstructural parameters and layer disorder accompanying dehydration transformation in Na-montmorillonite

Structural changes accompanying thermal transformation in Na-montmorillonit e samples up to a temperature of 500 degrees C have been investigated by X- ray line profile analysis. The method of Fourier initial slope and variance analysis of X-ray line profiles have been used to calculate the different microstructural parameters like crystallite size, r.m.s. strain ([e(2)](1/2 )), variation of inter layer spacing (g), fraction of planes affected by su ch defects (gamma), etc, at different stages of the dehydration process. Th e dehydration mechanism also has been explained based on thermogravimetric analysis (TGA).