Ultrastable metallic glasses (SMGs) formed by physical vapor deposition are an interesting new class of material, exhibiting enhanced stability argued to be equivalent to conventionally quenched metallic glasses that have been aged for thousands of years. The factors controlling the formation and structural development of SMGs are still not well understood. For the first time, the impact of film thickness toward the development of SMGs was explored. By controlling the thickness, we can tune the thermophysical and mechanical properties of SMGs. Geometrical and statistical analyses indicate that the films initially contain loose-packing phases that tend to elongate and present with a larger average size and less dispersive distribution as a result of induced geometric confinement. As the film is built up, structural heterogeneity develops, leading to variations in properties as the glass undergoes rejuvenation. This study provides direct evidence for the structural changes underlying the unique properties of SMGs and challenges the empirical rules for SMGs design.

通过物理气相沉积形成的超稳定金属玻璃（SMG）是一类有趣的新型材料，具有增强的稳定性，据称与已经老化数千年的传统淬火金属玻璃等效。控制SMGs的形成和结构发展的因素仍然不是很了解。首次探讨了膜厚对SMG发展的影响。通过控制厚度，我们可以调整SMG的热物理和机械性能。几何和统计分析表明，薄膜最初包含疏松堆积相，由于诱发的几何限制，这些堆积相往往会伸长并呈现出较大的平均尺寸和较小的分散分布。随着胶卷的堆积，结构异质性不断发展，随着玻璃的复兴，导致性能变化。这项研究为SMG独特属性的基础结构变化提供了直接证据，并向SMG设计的经验规则提出了挑战。