Nano Scale Calculations on Surface on Modifications by Ion Beam and on Hydrogen Hosting with Boron Clusters their Compounds

In this presentation selected results of our recent studies on classical simulations of ion-cluster collisions and quantum mechanical works of hydrogen hosting on bare boron and boron containing clusters will be discussed. Ar+ - Ni interactions have been studied via constant energy Molecular dynamic simulation. The Ni cluster around room temperature is mimicked by an embedded-atom potential, and the interaction between the projectile and the cluster is modelled by using screened Coulomb type ZBL potential. Ni clusters of 1000-5000 atoms and 10-40 eV projectile energies have been examined. Hamilton's equations of motion were solved for all the atoms in our system using Hamming's modified fourth order predictor corrector propagator with a step size of 1x10-15 s. At each impact energy and angle, 1000 trajectories are evolved. For each trajectory, the development of the collision cascade has been followed for up to 3.5 ps, which is much longer than the typical sputtering time. The time is set to t=0 when the projectile starts moving towards the cluster at a distance of 9.5 A above the cluster surface. Hydrogen storage as being the energy source of the future is still one of the big issues to be resolved in spite of the major improvements in this area. Previously, we have studied the pure boron clusters and their hydrogen storage ability, in detail at nano scale. Gaussian03 program has been used for all calculations with 6-31g and 6-311++g(d,p) basis sets. For the further studies, the hydrogen storage properties of small LinBm and metallo borane clusters such as AlnBm are in progressive investigations by means of density functional theory. We have chosen the B6 cluster as the starting point and replaced the boron atoms one at a time, in a step wise manner, with the Li atoms. For these new structures we have searched for the stable configurations, and calculated their energies, Homo-Lumo energy gaps, Raman and infrared spectra, average boron charge distribution, and vibrational frequencies