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transform IR (FTIR) spectroscopy (Biorad FTS6000) by the disappearance of the C±H stretching vibration peak at 2840±2970 cm ±1 . X-ray diffraction (XRD) patterns were taken on a RINT-2100 (Rigaku) diffractometer using Cu Ka radiation. In-plane XRD measurements were performed on an ATX-G (Rigaku) diffractometer using Cu Ka radiation.

Direct in situ optical and photoelectron emission microscopy observations of the nucleation and growth of VO(2) meso- and nanostructures using thermal transport of V(2)O(5) precursor in a vacuum or in an inert-gas environment were conducted. During nanostructure reductive growth, the formation, coexistence, and transformation of the intermediate oxide phases and morphologies were observed and characterized structurally and compositionally. The composition, structure, and morphology of the resultant nanostructures appeared to be a product of the interplay between kinetic and thermodynamic factors during multiple phase transformations. By rationally "navigating" the growth parameters using knowledge of the vanadium-oxygen temperature-composition phase diagram, wetting behavior, and epitaxial relationships of the intermediate phases with the substrate, control over growth direction, faceting, shape, and elastic strain of the nanostructures can be achieved. Such versatile control over the properties of single-crystal VO(2) nano- and mesostructures will facilitate their application in MEMS, sensors, and optoelectronics.

The structure of disordered GaN:O films grown by ion-assisted deposition is investigated using x-ray absorption near-edge spectroscopy and Raman spectroscopy. It is found that between 4 and 21% of the nitrogen in the films is in the form of molecular N 2 that interacts only weakly with the surrounding matrix. The anion to cation ratio in the GaN:O host remains close to unity, and there is a close correlation between the N 2 fraction, the level of oxygen impurities, and the absence of crystalline order in the GaN:O matrix.

Deposition of mixtures of palmitic acid (C15H31COOH) and perfluorooctadecanoic acid (C17F35COOH) onto solid substrates gives rise to irregularly shaped, phase-separated domains under a variety of deposition conditions. The morphology and chemical composition of these phase-separated domains have been investigated using a combination of surface pressure-area isotherms, atomic force microscopy, X-ray photoemission electron microscopy, and confocal fluorescence microscopy imaging. While domain morphology and composition in 2D phase-separated mixed monolayer systems can typically be rationalized in terms of an interplay between line tension and dipole-dipole repulsion effects, it was found that for this system additional kinetic factors, including domain growth rates and the rate of dissolution of the fatty acid component into the aqueous subphase, also play a major role in controlling film properties. The potential importance of these effects for the controlled patterning of solid substrates is discussed.

Stoichiometric amorphous GaN thin films have been grown by an ion-assisted deposition method and examined by x-ray photoelectron spectroscopy and x-ray absorption near-edge spectroscopy (XANES). The crucial question is the nature of the local structure around the N and Ga in the x-ray amorphous films. The N K edge XANES has been used to determine coordination around the N centre and reveals substantial differences to crystalline GaN. Although the transitions observed mirror those of the crystalline material and are consistent with density of states calculations, the low-energy peak at ∼402 eV is dominant in all films less than ∼150 nm in thickness. This peak, initially attributed to an sp 2 environment, is associated with the presence of molecular nitrogen. For thicker films, a duplex-type structure is observed with a surface layer much closer to the structure of the crystalline material.

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