The formation of highly coherent double-shelled L1₂ nano-precipitates in dilute Al–Er–Sc–Zr alloys was investigated with the combined use of Cs-corrected transmission electron microscopy characterization and first-principles energetics calculations. The double-shelled nano-precipitates are primarily featured with an Er-rich core surrounded by a Sc-rich inner shell and a Zr-rich outer shell. First-principles energetics analyses based on the classic homogenous nucleation theory suggested that once forms, this double-shell structure can be thermally stable. The predominant formation of this double-shell structure has thus both profound kinetic and thermodynamic origins. Its formation and stability preference to all other possible L1₂ nano-structures would become more pronounced as its size increases, no matter what the solute ratio and aging temperature of interest.

结合使用 Cs 校正透射电子显微镜表征和第一性原理能量学计算，研究了在稀释的 Al-Er-Sc-Zr 合金中形成高度相干的双壳 L1 ₂纳米沉淀物。双壳纳米沉淀物的主要特征是富含 Er 的核被富含 Sc 的内壳和富含 Zr 的外壳包围。基于经典同质成核理论的第一性原理能量学分析表明，这种双壳结构一旦形成，就可以是热稳定的。因此，这种双壳结构的主要形成具有深刻的动力学和热力学起源。它的形成和稳定性优先于所有其他可能的 L1 ₂ 无论感兴趣的溶质比和老化温度如何，纳米结构都会随着其尺寸的增加而变得更加明显。