Recently, gold nanoribbons (Au NRBs) with hexagonal (4H) phase have emerged as a new kind of ultrathin Au nanostructure with unusual metastable crystal phase, which could possess unique physiochemical properties and various promising applications. However, its geometric structure and phase stability under realistic service conditions, like Joule heating or external thermal loading, have not been well studied. Here, we systematically investigated the thermal responses in geometries and crystalline phases of ultrathin 4H Au NRBs under controlled in situ heating. It is found that upon moderate electron beam irradiation heating below 400 K, “Rayleigh instability” can be gradually observed, showing an obvious geometric effect, but the 4H phase remains stable. However, phase transition from 4H to face-centered cubic phases occurs when heating temperature approaches 800 K by using a dedicated microelectromechanical system heating chip, which agrees well with the result obtained by molecular dynamics simulations.

近年来，具有六方（4H）相的金纳米带（Au NRBs）作为一种新型超薄金纳米结构出现，具有不寻常的亚稳态晶体相，具有独特的理化性质和广阔的应用前景。但是，在实际使用条件下，如焦耳加热或外部热负荷，其几何结构和相稳定性尚未得到很好的研究。在这里，我们系统地研究了在受控原位条件下超薄4H Au NRB的几何和晶相中的热响应加热。发现在中等电子束辐射加热到400 K以下时，可以逐渐观察到“瑞利不稳定性”，表现出明显的几何效应，但4H相保持稳定。但是，通过使用专用的微机电系统加热芯片，当加热温度接近800 K时，会发生从4H到面心立方相的相变，这与分子动力学模拟获得的结果非常吻合。