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The groundbreaking properties of biaxially textured thin films have attracted increasing attention to the characterization and growth theory of their crystal morphologies. In particular, multi-faceted columnar structures developed during oblique angle deposition (OAD) show abnormal tilt angles that have not been previously captured by existing models. Current theories for the formation of biaxially aligned columnar structures overlook the fact that the surface diffusion on individual facets can be finite. In this work, a continuum model incorporating finite adatom mobility, flux-dependent sticking coefficient and material-specific surface energies is employed to study the growth of a well-known MgO-OAD system. Experimentally observed morphologies are reproduced by simulating the shadowing growth of an array of preferentially oriented single crystals. We show that the abnormal tilting is elusive considering only the effects of faceting and shadowing. A proposed sticking coefficient in our model, determined by the component of adatom momentum parallel to the surface, is responsible for the development of abnormal tilting. The role of faceting is demonstrated by its effect on the resulting columnar morphologies. Using the proposed model, the characteristic morphology and tilting behavior of a CaF 2-OAD system are also obtained which agree with experiments.

Considered as one of the ultimate energy storage technologies for electrified transportation, the emerging all-solidstate batteries (ASSBs) have attracted immense attention due to their superior thermal stability, increased power and energy densities, and prolonged cycle life. To achieve the expected high performance, practical applications of ASSBs require accurate and computationally efficient models for the design and implementation of many onboard management algorithms, so that the ASSB safety, health, and cycling performance can be optimized under a wide range of operating conditions. A controloriented modeling framework is thus established in this work by systematically simplifying a rigorous partial differential equation (PDE) based model of the ASSBs developed from underlying electrochemical principles. Specifically, partial fraction expansion and moment matching are used to obtain ordinary differential equation based reduced-order models (ROMs). By expressing the models in a canonical circuit form, excellent properties for control design such as structural simplicity and full observability are revealed. Compared to the original PDE model, the developed ROMs have demonstrated high fidelity at significantly improved computational efficiency. Extensive comparisons have also been conducted to verify its superiority to the prevailing models due to the consideration of concentration-dependent diffusion and migration. Such ROMs can thus be used for advanced control design in future intelligent management systems of ASSBs.

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Anatase TiO 2 nanorods with a well-defined h110i texture have been studied using a model-based characterization technique based on a previous modeling framework. Intricate secondary side facet characteristics of tilt angles of 26:5 have been indexed, and a h112i growth direction of the well-aligned facets is identified. These results have not been accessed experimentally but crucial in understanding the nature of the most abundant facets and their structural properties. We find agreement between our results and indirect experimental measurements. Highly exposed {116} facets are found to be responsible for excellent electrochemical surface properties in nanostructured anatase TiO 2 thin films.