On the Decomposition of Synthetic Gibbsite Studied by Neutron Thermodiffractometry

Abstract

The thermal decomposition mechanism of synthetic Al(OH) 3 (gibbsite) was studied in situ by neutron thermodiffractometry in an ambient atmosphere from room temperature to 600°C with 50°C steps. Gibbsite decomposed to yield AlO·(OH) (boehmite) and then poorly crystallized χ‐Al 2 O 3 . Rietveld analysis was used to refine the cell parameters' variation of gibbsite and its thermal expansion coefficients were obtained: for the a ‐axis: 15±1 × 10 −6 K −1 , for b : 10±2 × 10 −6 K −1 , and for c : 17±2 × 10 −6 K −1 .