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195187 https://hdl.handle.net/2286/R.2.N.195187 http://rightsstatements.org/vocab/InC/1.0/ All Rights Reserved 2024 57 pages Masters Thesis Academic theses Text eng Bedner, Michael Salomão Birkel, Christina Seo, Dong-Kyun Navrotsky, Alexandra Arizona State University Partial requirement for: M.S., Arizona State University, 2024 Field of study: Chemistry MAX phases are a class of ternary layered carbides and nitrides following the general formula Mn+1AXn. M is typically an early transition metal, A is a main group element, and X represents carbon and/or nitrogen. A greater variety (e.g. late transition metals on the A-site) have been shown in the last few years.1 These layered materials crystallize in the P63/mmc space group with A elements intercalated between layers of edge-sharing M6X octahedra and display favorable properties of both metals and ceramics. Much of the work in exploring new MAX phases has risen from finding new M, A, and X elements from which to compose novel MAX phases, and an emerging area of interest lies in synthesizing solid solutions where two or more M, A, or X elements are alloyed in the crystal lattice. To date, at least 152 MAX solid-solutions have been synthesized, with 46 being A-site solid solutions and only 35 of which are synthesized via bottom-up synthesis methods. In this work, a new A-site solid solution is presented with the formula Nb2In1-xSnxC, where x = 0, 0.1, 0.2, …, 1. The parent MAX phases Nb2InC and Nb2SnC, as well as the full solid solution between the two, were synthesized in a bottom-up fashion where metal powder precursors were mixed and pelletized under argon atmosphere before heat treatment in a sealed ampule under static vacuum. Samples were acid-washed in glacial hydrochloric acid (HCl) to remove metallic impurities before further characterization. The washed samples were characterized using X-ray diffractometry (XRD), Scanning Electron Microscopy (SEM), and Energy-dispersive X-ray Spectroscopy (EDS). Electron micrographs revealed layered morphology consistent with MAX phase lamination and honeycomb-like structures consistent with hexagonal crystal systems. EDS verified the ratio of indium to tin in the samples was consistent with the stoichiometry of each experiment. Transmission mode XRD data were refined in GSAS-II software to determine lattice parameters of the solid solution series, where a robust linear trend was observed, indicating that the change in parameters was in close agreement with Vegard’s law. These findings confirm the new addition to the MAX phase A-site solid solution catalog. Chemistry A-site solid solution MAX Phases solid solutions A-site Solid Solution Between MAX Phases Nb2InC and Nb2SnC