Metal,Alloy Nanoscale System Computation And Simulation

From the development of the potentials and possibilities that Nano Sci-Technology presents, it is clear that the computation and simulation of nanoscale materials will continue to become increasingly important. To study of simulations, it is necessary to use the description of the interaction between atoms. The accuracy of the potential used dictates the quality of the simulation results. For nanoscale materials system, There haven't a uniform model or method to study the details of the nanoscale material designed and function. There have been quite a bit of development to utilize the empirical interatomic potential, but the applicability is inherently limited to easy causing a transferability problem. In the paper, we develop a appropriate interatomic potential via density functional theory(DFT) , simulate well in nanoscalematerial system. There are three sections in this paper.1. Computational simulation in nano size metal clusterIn chapter 2, We use DFT to calculate equilibrium geometries and electronicproperties of Cun(n=2-13) clusters and construct potential function with parameters fitted to potential energy surfaces, use a global minima "basin-hopping" algorithm to obtain minimum-energy structures of Cu clusters for n=13~410. The results show in good agreement with experiments and other calculations. There haven't a same result for the simulation of Thallium cluster, owing to different electronic structure. This shows that the potential energy function limit to use in certain condition.2. Computational simulation in nano size alloy systemChapters, We applied an approach to the development of many-body interatomic potentials for NiTi, NiZr alloys, The database used for the development of a potential includes both experimental data and a large set of energies of different structures of the material generated by DFT calculations. The molecular dynamic simulation results prove the structure change in nano materials grain size. The thermodynamic and mechanical properties are calculated, it shows the melting point reduce in NiZr alloy nano material. Further we study the microstructure of them by the Reverse Monte Carlo simulation, obtain the a series of information about bond angle - coordinateand so on.3. Metal supported On Ti02(110): Calculation and SimulationChapter 4, The properties of K, Cu supported on the TiO2(110) surfacehave been studied by means of density functional theory, Bare clusters models and embedded cluster model to using to obtain DFT data and construct interatomic potential. The simulation results can explain some phenomena in STM image.In chapter 5, we study in detail the theoretical background , function express and improvement, try to find a relation with other model and method. For a new embedded atom potential, we apply it to simulate copper nanowire structure and energy.