In situ transmission electron microscopy observation of the decomposition of MgH2 nanofiber

In this paper, we presented an investigation of the phase transformation of MgH2 to Mg, in which a sample of a single-crystal MgH2 nanofiber was prepared by hydriding chemical vapor deposition (HCVD) and observed by in situ (high-resolution) transmission electron microscopy (TEM). The results indicated that the orientation relationship between MgH2 and Mg during the phase change was: one of the zone axis of MgH2 <110> parallel to Mg [0001] zone axis, or one of the plane {110} of MgH2 parallel to the basal plane of Mg (0001). On the basis of the obtained results, we proposed a structural model for the phase change of MgH2 to Mg.