Title of Dissertation: DEVELOPMENT AND APPLICATIONS OF MULTIFREQUENCY IMAGING AND SPECTROSCOPY METHODS IN DYNAMIC ATOMIC FORCE MICROSCOPY Gaurav Chawla, Doctor of Philosophy, 2011 Dissertation directed by: Assistant Professor Santiago D. Solares, Department of Mechanical Engineering Force spectroscopy and surface dissipation mapping are two of the most important applications of dynamic atomic f...

We compare fluctuation electron microscopy data to simulations from phenomenological atomic models and demonstrate a strong correspondence between some features in the experimental data and certain atomic configurations. This allows the nature of atomic clustering in a highly hydrogenated diamondlike carbon to be determined more closely. We compare the structural information garnered from fluct...

We present an Al2O3 dielectric layer on molybdenum disulfide (MoS2), deposited using atomic layer deposition (ALD) with ozone/trimethylaluminum (TMA) and water/TMA as precursors. The results of atomic force microscopy and low-energy ion scattering spectroscopy show that using TMA and ozone as precursors leads to the formation of uniform Al2O3 layers, in contrast to the incomplete coverage we ob...

The atomic structure of a well-ordered silica film grown on a Mo(112) single crystal substrate is discussed in detail using the experimental and theoretical results available to date. New photoelectron spectroscopy results using synchrotron radiation and ultraviolet spectroscopy data are presented. The analysis unambiguously shows that the ultra-thin silica film consists of a two-dimensional ne...

Atomic column elemental mapping is realized by electron energy loss spectroscopy (EELS) and/or energy dispersive X-ray spectroscopy (EDS) [1], with modern technologies of electron microscopy such as an aberration corrector [2]. The method is widely utilized in materials and physical sciences, since atomic species and positions in a crystalline specimen can be determined directly. A crucial issu...

We describe the operation of two GaN-based diode lasers for the laser spectroscopy of gallium at 403 nm and 417 nm. Their use in an external cavity configuration enabled the investigation of absorption spectroscopy in a gallium hollow cathode. We have analyzed the Doppler broadened profiles accounting for hyperfine and isotope structure and extracting both the temperature and densities of the n...

Hexagonal boron nitrite (h-BN) is an attractive material for many applications including electronics as a complement to graphene, anti-oxidation coatings, light emitters, etc. However, the synthesis of high-quality h-BN is still a great challenge. In this work, via controlled chemical vapor deposition, we demonstrate the synthesis of h-BN films with a controlled thickness down to atomic layers....

Atomic-layer 2D crystals have unique properties that can be significantly modified through interaction with an underlying support. For epitaxial graphene on SiC(0001), the interface strongly influences the electronic properties of the overlaying graphene. We demonstrate a novel combination of x-ray scattering and spectroscopy for studying the complexities of such a buried interface structure. T...

Towards the development of a useful mechanism for hydrogen storage, we have studied the hydrogenation of single-walled carbon nanotubes with atomic hydrogen using core-level photoelectron spectroscopy and x-ray absorption spectroscopy. We find that atomic hydrogen creates C-H bonds with the carbon atoms in the nanotube walls, and such C-H bonds can be completely broken by heating to 600 degrees...