Theoretische Untersuchungen zu Wachstum, Stabilität und Funktionalität von Nanodrähten

纳米线具有迷人的光学，电学和磁学性质，与宏观系统有很大不同。此外，它们的结构演化的驱动力的种类和强度可以完全不同，从而为它们的合成开辟了新的途径。此外，纳米线是不稳定的，并且在其衰变期间经常形成自组织的纳米结构。该项目旨在基本了解（i）纳米线的合成，（ii）治疗过程中的形状演变，以及（iii）功能结构的制造。将进行系统的理论研究，以了解在何种条件下1D前体结构（例如注入剖面;沉积材料的条纹）向纳米线发展。关于形状演变的目的是双重的：一方面，它将研究纳米线如何承受热处理而不衰减（瑞利不稳定性）。另一方面，我们寻找一个控制的珍珠不稳定性，以产生功能结构，如量子点链。在这方面，对于单晶线，如CoSi 2在Si中的晶体取向对纳米线稳定/不稳定的影响是首次通过原子模拟研究的重要问题。对于特定的实验（离子轨道线在GSI，纤维束线在FZR）的原子模拟预测将作为纳米线的合成和修改的指导方针。模拟将使用完善的独特3D动力学晶格蒙特卡罗程序包进行。

Nanowires have fascinating optical, electrical and magnetic properties which can differ significantly from macroscopic systems. Also the kind and strength of driving forces for their structural evolution can be completely different, thus opening new routes for their synthesis. Additionally, nanowires are thermodynamically instable and form frequently self-organized nanostructures during their decay. This project aims at the fundamental understanding of (i) the synthesis of nanowires, (ii) their shape evolution during treatments, and (iii) the fabrication of functional structures. Systematic theoretical studies will be performed to understand under which conditions 1D precursor structures (e.g. implantation profiles; stripes of deposited material) evolve towards nanowires. Concerning the shape evolution the aim is twofold: On the one hand, it will be studied how nanowires withstand thermal treatments without decay (Rayleigh instability). On the other hand, we search for a control of the pearling instability to produce functional structures like quantum dot chains. In this connection, for monocrystalline wires like CoSi2 in Si the impact of crystal orientation on nanowire stabilization/destabilization is an important issue to be studied for the first time by atomistic simulations. For specific experiments (ion-track-wires at GSI, FIB-wires at FZR) predictions of atomistic simulations will serve as guidelines for nanowire synthesis and modifications. The simulations will be performed with a well-established unique 3D kinetic lattice Monte Carlo program package.