Synthesis, Characterization, and Exfoliation of Ternary Layered Borides
This work examines the structural layering of ternary intermetallic borides. A new crystal structure, Nb(1-x)Os(1+x)B, has been discovered, exhibiting infinite boron chains and isolated boron atoms. Computational work done with DFT shows that the partial osmium substitution occurs both for geometric reasons due to the size difference, and for electronic reasons. The increased valence electron count (VEC) greatly stabilizes the boron chain fragment, at the cost of a slight global destabilization. Work is also done on exfoliating layered MAB structure M2AlB2 (M=Cr, Mn, Fe) in 2d sheets. Aluminum etching from the structure is achieved, and morphological as well as chemical characterization is demonstrated.