A XANES study on the dehydration process of magnesium hydroxide

Abstract The process of MgO formation by dehydration of Mg(OH) 2 has been studied by Mg K-edge XANES which reflects surface structures. Based on the simulation of XANES spectra of Mg(OH) 2−2 x O x by superposition of XANES of Mg(OH) 2 and MgO, the composition of these two species was evaluated. The ratio of MgO to Mg(OH) 2 in the surface layers was higher than that in the bulk which was estimated by XRD and the degree of dehydration, indicating that the formation of MgO phase occurs from surface to inside.