Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa, 32000, Israel.
Science. 2011 Apr 8;332(6026):206-9. doi: 10.1126/science.1201596.
Nanometer-thick films at interfaces and surfaces exist in various materials and can substantially influence their properties. Whether these films are an equilibrium or transient state is debated. To address this question, we equilibrated 1.2-nanometer-thick films at gold-sapphire interfaces in the presence of anorthite glass and measured the solid-solid interface energy. The equilibrated film significantly reduced the interfacial energy and could be described by the Gibbs adsorption isotherm expanded to include structure in addition to chemical excess. Unlike artificially made conventional thin films, these films do not break up during equilibration and offer an alternative design criterion for thin-film technology. These results demonstrate that nanometer-thick films at interfaces and surfaces can be an equilibrium state and included in phase diagrams with dedicated tie-lines.
界面和表面的纳米级薄膜存在于各种材料中，并且可以显著影响它们的性质。这些薄膜是平衡态还是瞬态态一直存在争议。为了解决这个问题，我们在钙长石玻璃的存在下平衡了金-蓝宝石界面处的 1.2 纳米厚的薄膜，并测量了固-固界面能。平衡后的薄膜显著降低了界面能，可以用吉布斯吸附等温线来描述，该等温线除了化学过剩之外，还扩展到包括结构。与人为制造的传统薄膜不同，这些薄膜在平衡过程中不会破裂，为薄膜技术提供了另一种设计标准。这些结果表明，界面和表面的纳米级薄膜可以是平衡态，并包含在带有专用连接线的相图中。
