Abstract Wafer curvature measurements reported in literature for polycrystalline (often textured) and epitaxial fcc metal thin films on hard substrates show a characteristic “signature” in the stress-temperature evolution for either type of films. While epitaxial films reveal characteristic elastic – ideal plastic deformation with no dislocation storage and highly repeatable cycles, polycrystalline films show considerable hardening upon cooling in addition to the relaxation by diffusional creep at elevated temperatures. In the present study, we study the deformation characteristics of an electron beam deposited epitaxial nanotwinned Ag on Si (111) substrate. The twin spacing λ of the nanotwinned Ag is controlled by suitable heat treatment and the “signature” thermomechanical deformation curves by wafer curvature measurements are recorded for twin spacings varying from 20 nm to 1 μm. Further, deformation is compared to other small scale deformation studies on fcc metals such as epitaxial bicrystal films, bicrystal micropillars containing a coherent twin boundary and nanotwinned micropillars.

中文翻译：

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纳米孪晶银薄膜在热应力下的位错塑性和解缠

摘要 文献中报道的关于硬基板上的多晶（通常是织构的）和外延 fcc 金属薄膜的晶片曲率测量结果显示，这两种薄膜在应力-温度演变中都具有特征性的“特征”。虽然外延薄膜显示出特征性的弹性-理想塑性变形，没有位错存储和高度可重复的循环，但多晶薄膜除了在高温下通过扩散蠕变引起的松弛外，还显示出在冷却时相当大的硬化。在本研究中，我们研究了在 Si (111) 衬底上电子束沉积外延纳米孪晶 Ag 的变形特性。纳米孪晶 Ag 的孪晶间距 λ 由适当的热处理控制，并且通过晶片曲率测量记录了孪晶间距从 20 nm 到 1 μm 的“特征”热机械变形曲线。此外，变形与 fcc 金属的其他小规模变形研究进行了比较，例如外延双晶膜、包含相干孪晶边界的双晶微柱和纳米孪晶微柱。