The lattice spacing of (200)Mg2Ni, which has the secondstrongest
diffraction peak in the XRD pattern of the polycrystalline
Mg2Ni [16], was often visible in the HRTEM image. STEM–EDS
mapping showed that the Ni was concentrated at the nanocrystals.
This result also indicates that the 6Mg–Ni film is composed of a
Mg-rich amorphous matrix and nanocrystalline Mg2Ni. We
hypothesize that the crystallization of Mg2Ni is due to the initial
composition of 6Mg–Ni between the eutectic point and Mg2Ni.
Fig. 3 shows the STEM–EDS elemental maps of Mg, Ni, and Pd for
the 6Mg–Ni film. Pd diffused into the 6Mg–Ni film and Mg diffused
into the Pd layer.