Bimetallic clusters as model systems for the alloy formation

化学成分的变化为控制小团簇的化学和物理行为开辟了新的可能性。由于目前对这种纳米合金知之甚少，合金团簇的几何、能量、介电、磁性和光学性质将在这里提出的研究项目中进行系统的研究。在气相中形成的聚簇的第一个其次是质谱，这已经提供了重要的提示，对个别集群组合物的稳定性。特别是稳定的簇物种的几何和电子结构，然后研究量子化学方法。将这些结果与电子束和磁束偏转实验以及光学吸收光谱进行比较，不仅可以识别最低能量的结构异构体，而且可以得出有关纳米合金的磁性和光学行为以及合金颗粒不同原子之间的化学键合特性的重要结论。这些研究可以从本质上理解和跟踪从单原子到介观尺度的过渡，从而有助于探索纳米合金的潜在应用。

A variation of the chemical composition opens up new possibilities to control the chemical- and physical behaviour of small clusters. Since still little is known so far about such nanoalloys, the geometric, energetic, dielectric, magnetic, and optical properties of alloyed clusters are going to be investigated systematically in the research project presented here. The formation of the bimetallic clusters in the gas phase is first followed by mass spectrometry, which already provides important hints on the stability of individual clusters compositions. The geometric and electronic structure of particularly stable cluster species is then studied by quantum-chemical methods. A comparison of these results with electric and magnetic beam deflection experiments as well as optical absorption spectra can not only identify lowest energy structural isomers, but also draw important conclusions about the magnetic and optical behavior of nanoalloys and the chemical bonding characteristics between different atoms of the alloy particles. The investigations allow to essentially understand and to follow the transititon from single atoms to mesoscopic length scales and thus help to explore potential applications of nanoalloys.