A Simple and Sensitive Method for Simultaneous High-Temperature X-ray Powder Diffraction and Thermogravimetric Analysis

An apparatus is described for simultaneous high-temperature X-ray powder diffraction and thermogravimetric studies, based on a Guinier-Lenné focusing powder camera and an analytical chemical balance. No modifications are required to either instrument and the method would be readily useable with many other types of high-temperature powder diffraction systems. The technique is illustrated by a study of the dehydration reactions in an artists' plaster containing gypsum. A sensitivity to changes in weight approaching 100 μg in a 12.5 mg sample was achieved over a period of 60 h.