Nanotechnology is the manipulation of matter at a molecular scale, a technological feat that has only risen to prominence in recent decades. Engineered nanostructures show incredible potential, but have required the development of new and powerful tools both in their production and in their characterization. Continued progress in nanotechnology is founded on the continued improvement of these tools, extending our control over structures dwarfed even by the cells that comprise us. Glancing angle

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... deposition (GLAD) is one such tool. Without costly substrate patterning, GLAD uses traditional physical vapour deposition to produce arrays of individual nanostructures out of a vast and ever-growing variety of materials. Through simple substrate rotation, these structures can be sculpted with an astonishing degree of control, producing both the graceful spirals of helical morphologies and the stolid workhorse that is the vertical post film-vertically oriented nanorods that are common candidates for device applications. Research into GLAD applications drives interest in better understanding their growth mechanics, allowing better control of their shape Better control of GLAD morphology requires better understanding of GLAD growth. and properties. It is not surprising, then, that the GLAD vertical post has attracted much investigation. These posts broaden as they grow, an oft undesirable phenomenon that is not yet fully understood. Control of this broadening effect requires a more detailed understanding of its causes. The width of these columns is thought to obey the power law where d is the column width in nm, ω 0 is a material-dependant constant, h is the height above the substrate, and p is an exponent that describes the posts' growth scaling. Theory also predicts upper and lower limits on this value, which numerous groups have attempted to test experimentally. Results are inconsistent from group to group, Broadening measurements are challenging, and literature results are inconsistent. difficult to repeat, and obey few clear trends, with data outside both predicted limits. Some factors potentially affecting p, such as the effect of substrate rotation rate on vertical post morphology, have not yet been quantitatively studied. A further obstacle to repeatability comes from the difficulty in manually distinguishing nanocolumns from their neighbours, especially in densely branching oxide films. 1 1.2 outline