Neutral silver clusters, Ag(n), were studied using density functional theory (DFT) followed by high level coupled cluster CCSD(T) calculations to determine the low energy isomers for each cluster size for small clusters. The normalized atomization energy, heats of formation, and average bond lengths were calculated for each of the different isomeric forms of the silver clusters. For n = 2-6, the preferred geometry is planar, and the larger n = 7-8 clusters prefer higher symmetry, three-dimensional geometries. The low spin state is predicted to be the ground state for every cluster size. A number of new low energy isomers for the heptamer and octamer were found. Additional larger Ag(n) structures, n < 100, were initially optimized using a tree growth-hybrid genetic algorithm with an embedded atom method (EAM) potential. For n ≤ 20, DFT was used to optimize the geometries. DFT with benchmarked functionals were used to predict that the normalized atomization energies ((AE)s) for Ag(n) start to converge slowly to the bulk at n = 55. The (AE) for Ag99 is predicted to be ~50 kcal/mol.

Hafnium oxide ultra thin films on Si (100) are being developed to replace thermally grown SiO 2 gates in CMOS devices. In this work, a specially designed Attenuated Total Reflectance -Fourier Transform Infra Red Spectroscopy (ATR-FTIR) reaction cell has been developed to observe chemisorption of hafnium (IV) t-butoxide onto a Si and Ge ATR crystal heated up to 250°C and under 1 torr of vacuum to observe the initial reaction pathways and species on the substrate surface in real time and under typical process conditions. Chemisorption spectra were compared to spectra of the liquid precursor and to spectra generated by density functional theory (DFT) calculations of liquid, monodentate and bidentate absorbed precursor. An asymmetric stretching mode located at ~1017 cm -1 present in the chemisorbed spectra but not in the liquid spectra indicates that the adsorbed hafnium containing group is prevalent as a bidentate ligand according to calculations. Surface concentration of the chemisorbed species was dependant on the substrate temperature and precursor partial pressure allowing for determination of heats of adsorption which was 26.5 kJ/mol on Si.