Description
1st Paragraph: Crystallization mechanisms involving sequential particle attachment have been the focus of many recent studies as an alternative to classical nucleation and growth strategies [1]. The latter considers only growth via atom-by-atom or molecule-by-molecule mechanisms, whereas particle attachment considers the construction of bulk materials from nanoparticles that have nucleated from a solution and subsequently agglomerated in an orderly fashion. This gives rise to an interesting hierarchy of particulate morphologies that themselves are building blocks for larger structures. Many of the studies reported on thus far have focused on multi-particulate growth from homogeneous solution environments [2,3,4]. Alternatively, we report here on a “heterogeneous” growth process whereby nucleation, growth and assembly of nanoparticles are very much restricted to a thin, nearly 2D reaction zone at substrate surfaces. The process is very much akin to a gas phase deposition system, but involving the continuous spraying of fresh aqueous reactants. We found interesting patterns of 1D, 2D and 3D particulate superstructures as a function of the processing conditions. This very much includes the influences of the fluid dynamics of the sprayed reactants and liquid byproducts.
Authors: Kaushik Sridhar Vadari Venkata, Nicole M. Ray, and William T. Petuskey
Keywords: Magnetite, Nucleation and Growth, Self-Assembly, Agglomeration, Superstructures