摘要
A novel Fe-enriched lamella sandwich phase (χ-phase) has been found to precipitate along the basal (0001)_(Mg) planes in the heat-treated Mg-Gd-Fe alloy and its structure is clearly revealed by means of atomic-resolution transmission electron microscopy.The layered χ-phase only has a thickness of mono-unit-cell and consists invariably of ten atomic layers stacking along the[0001]_(Mg) direction,of which the outermost atomic layers had larger in-plane atom-pillar spacing than the inner layers.Fe/Gd atoms are mainly enriched in the outer four atomic layers in the χ-phase,forming two structurally unsymmetrical four-layer shells to sandwich the middle two Mg layers.An atomic model has been proposed for this layered sandwich-structured χ-phase.
基金
Funded by the National Natural Science Foundation of China(No.11274027)
Beijing Municipal Natural Science Foundation(No.2092005)。