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Structures grown via self-assembly are a unique field in nanotechnology. The morphology of self-assembled structures is affected by the balance between kinetics and thermodynamics during growth. Hence structures with tailored morphologies and properties can be created with adjustments in growth conditions. In this thesis we study crystal nucleation and equilibration, for both real and model systems. The growth of thin bismuth films is investigated on three atomically flat surfaces; Mica, Molybdenum di Sulphide, and highly oriented pyrolitic graphite (HOPG). Films are grown under UHV conditions, and characterised using scanning electron microscopy and atomic force microscopy. For coverages of only a few monolayers, bismuth particles are found to aggregate into flat, isolated islands. Islands have characteristic heights and morphologies for each substrate. By altering the deposition flux and coverage, the island density and morphology can be manipulated. On HOPG substrates, planar islands grown at low flux are replaced by 1D structures at high temperature. These anisotopic structures result from an anisotropy in bond strengths at the crystal-vapour interface. Depositing Bi on HOPG substrates at low flux or high temperature conditions produces nanorods aligned (roughly) perpendicular to step edges on the graphite. The aspect ratios (ARs) of these 1D structures are found to increase as the deposition flux is lowered, or the substrate temperature is increased. The Arrhenius dependence of the AR is determined from experiment. A Kinetic Monte Carlo (KMC) model for high AR step-edge aggregates was developed, determining the likely growth mechanism for the nanorods. A scaling regime devised from the KMC results predicts the dependence of nanorod ARs on flux and temperature, and allows an estimation of the energy binding Bi dimers to the sides of nanorods. Thin films can also be grown via the self-assembly of atomic clusters. After deposition coalescence of clusters has implications for the film morphology, and properties. We use KMC simulations to investigate the coalescence of pairs of 3D atomic clusters (15000 to 130000 atoms in size) via lattice based surface diffusion. For early coalescence stages, the radius of the neck region connecting the two clusters is found to develop with a different powerlaw to classical theory. For later coalescence stages, when the nucleation of new atomic layers on facets of the cluster is required for further coalescence the temperature, cluster size, and cluster orientation all influence the coalescence. Equilibration times for clusters coalescing at high temperature are found to be limited by the dissociation of atomic layers.

The properties of surface plasmon polaritons which propagate in optically nonlinear or magnetic media are investigated. Expressions for the electromagnetic fields of a multilayer stack are derived by modification of the Fresnel reflection coefficients. Original research on prism-coupled, nonlinear, long-range surface plasmon polaritons, and on bound and prism-coupled, long-range surface magnetoplasmon polaritons in a transversely-applied magnetic field, is compared to previous research on single-interface plasmon polaritons. The reflectance from prism-coupled, nonlinear surface plasmons is analyzed using the infinite plane-wave approximation and a substrate nonlinearity which depends on the square of the transverse-electric field. Bistable switching requires incident intensities two orders of magnitude smaller for the long-range mode than for the single-interface mode. The regime in which the approximations are valid is shown to extend beyond that of first-order perturbation theory to guided waves that are very near cutoff. The sign and location of the nonlinearity become significant for these waves. For positive nonlinearities, nonlinear wave analysis indicates an additional branch of the reflected intensity curve, due to self-focussing of the guided wave. Positive and negative nonlinearities exhibit different switching intensities. The propagation constant of the long-range surface plasmon of a magnetic metal film is shifted by the application of a transverse magnetic field. The sign and magnitude of the shift are highly dependent on the metal thickness and the refractive indices of the bounding media. The shift is manifested experimentally as a resonant modulation of the reflectance from the prism-coupled surface plasmon due to changes in the angular position and width of the plasmon resonance. Experimental prism-coupling to the long-range surface magnetoplasmon in thin nickel films confirms the theoretical expectations for a wide variety of sample parameters. The phase of the magneto-optic coefficient is determined from the angular profile of the reflectance modulation. Although the shift of the propagation constant may be two orders of magnitude smaller for the long-range mode, the modulation signal is the same order of magnitude for long-range and single-interface magnetoplasmons.

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