Energy induced nanoparticle substrate interactions

已建立的自顶向下或自底向上的纳米颗粒合成方法通常接近或甚至处于热力学平衡状态，并且受到溶解度限制或表面重构的挑战。另一种选择是在特定环境中通过能量冲击对制备的纳米颗粒进行后续改性，以开发具有不寻常甚至奇异特性的新型纳米结构材料。更普遍的是，纳米颗粒的功能是由特定环境和/或支撑基质在给定能量影响下发生的相互作用过程赋予的！因此，界面上的演化和反应，特别是纳米颗粒和载体之间的反应，是非常重要的。不同的化学和物理过程发生在多个尺度上：例如，化学反应只发生在原子尺度上，热冲击导致界面合金的形成，离子冲击等过程导致原子的弹道混合。尽管已经分别研究了几个方面，但迄今为止还没有制定和获得所有有关过程的统一和一致的情况。确定在特定环境中由物理和/或化学能诱导的纳米颗粒衬底相互作用的相似性和差异性，一方面将促进具有特殊性能的新材料的开发，另一方面，明确其功能。正是这一挑战将在我们的联合提案中得到解决。我们的目标是确定化学和物理能量对金属纳米颗粒和硅基衬底材料之间相互作用的一般影响，以便深入了解潜在的过程。为了实现这一目标，我们将通过实验研究(a)热、(b)离子辐照和(c)化学反应在能量冲击过程中对支撑金属纳米颗粒阵列的化学和物理影响。纳米颗粒衬底在激光照射下的相互作用被广泛研究，发表的结果将与我们的实验结果一起用于得出全面的结论。结构演变将通过各种高分辨率技术进行监测，包括电子显微镜、电子色散x射线光谱学、电子背散射衍射和原子力显微镜。这三种平行的方法，加上我们的化学和物理背景，将使我们能够分离和确定潜在机制和影响的相互作用。纳米尺度上的表面和界面能/力、不同的晶体取向、相图、塑性流动、催化反应和化学键除了合金化和弹道混合之外，还必须考虑，以便全面有效地了解纳米颗粒-衬底在能量冲击下的相互作用。

Established top-down or bottom-up syntheses methods for nanoparticles often work close or even at thermodynamic equilibrium and are challenged by solubility limits or surface reconstructions. An alternative option is the subsequent modification of prepared nanoparticles by means of energy impact in a specific environment in order to develop new nanostructured materials with unusual or even exotic properties. Even more general, the functionality of nanoparticles is given by the occurring interaction processes with specific environments and/or supporting substrates upon a given energy impact! Thus, the evolution and reactions at interfaces, especially e.g. between nanoparticles and supporting substrates, are of great importance. Different chemical and physical processes take place at multiple scales: e.g. chemical reactions occur solely at atomic scales, thermal heat impact leads to the formation of interface alloys, and processes such as ion impact results in ballistic mixing of atoms. Even though several aspects have already been studied separately, a uniform and consistent picture of all involved processes has not been formulated and obtained until now. Identification of similarities and differences in nanoparticle substrate interactions induced by physical and/or chemical energy in specific environments would, on one hand, promote developing new materials with exceptional properties, and, on the other hand, specify their functionality.Exactly this challenge will be addressed in our joint proposal. We aim to identify the general impact of chemical and physical energy on the interaction between metallic nanoparticles and Si-based substrate materials in order to gain a deep understanding of the underlying processes. To achieve this goal, we will experimentally study chemical and physical effects on supported metal nanoparticle arrays taking place during energy impact by (a) heat, (b) ion irradiation, and (c) chemical reactions. Nanoparticle substrate interactions upon laser irradiation are vastly investigated, and the published results will be used to draw comprehensive conclusions together with our experimental results. The structural evolution will be monitored with various high-resolution techniques including electron microscopy, electron dispersive X-ray spectroscopy, electron back scattered diffraction, and atomic force microscopy. The three parallel approaches, with our chemical and physical background, will allow us the separation and the determination of the interplay of the underlying mechanism and effects. Surface and interface energies/forces at the nano-scale, different crystallographic orientations, phase diagrams, plastic flow, catalytic reactions and chemical bonding will and must be also considered besides alloying and ballistic mixing in order to obtain a full and valid understanding of nanoparticle-substrate interactions upon energy impact.