Arkady V. Krasheninnikov

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Both fullerenes and single-walled carbon nanotubes (SWNTs) exhibit many advantageous properties. Despite the similarities between these two forms of carbon, there have been very few attempts to physically merge them. We have discovered a novel hybrid material that combines fullerenes and SWNTs into a single structure in which the fullerenes are covalently(More)
We present an accurate measurement and a quantitative analysis of electron-beam-induced displacements of carbon atoms in single-layer graphene. We directly measure the atomic displacement ("knock-on") cross section by counting the lost atoms as a function of the electron-beam energy and applied dose. Further, we separate knock-on damage (originating from(More)
While crystalline two-dimensional materials have become an experimental reality during the past few years, an amorphous 2D material has not been reported before. Here, using electron irradiation we create an sp2-hybridized one-atom-thick flat carbon membrane with a random arrangement of polygons, including four-membered carbon rings. We show how the(More)
Using first-principles atomistic simulations, we study the response of atomically thin layers of transition metal dichalcogenides (TMDs)--a new class of two-dimensional inorganic materials with unique electronic properties--to electron irradiation. We calculate displacement threshold energies for atoms in 21 different compounds and estimate the(More)
Grain boundary (GB) migration in polycrystalline solids is a materials science manifestation of survival of the fittest, with adjacent grains competing to add atoms to their outer surfaces at each other's expense. This process is thermodynamically favored when it lowers the total GB area in the sample, thereby reducing the excess free energy contributed by(More)
Observations of topological defects associated with Stone-Wales-type transformations (i.e., bond rotations) in high-resolution transmission electron microscopy (HRTEM) images of carbon nanostructures are at odds with the equilibrium thermodynamics of these systems. Here, by combining aberration-corrected HRTEM experiments and atomistic simulations, we show(More)
Closed-shell carbon nanostructures, such as carbon onions, have been shown to act as self-contracting high-pressure cells under electron irradiation. We report that controlled irradiation of multiwalled carbon nanotubes can cause large pressure buildup within the nanotube cores that can plastically deform, extrude, and break solid materials that are(More)
Large-area graphene substrates provide a promising lab bench for synthesizing, manipulating, and characterizing low-dimensional materials, opening the door to high-resolution analyses of novel structures, such as two-dimensional (2D) glasses, that cannot be exfoliated and may not occur naturally. Here, we report the accidental discovery of a 2D silica glass(More)
Dislocations, one of the key entities in materials science, govern the properties of any crystalline material. Thus, understanding their life cycle, from creation to annihilation via motion and interaction with other dislocations, point defects and surfaces, is of fundamental importance. Unfortunately, atomic-scale investigations of dislocation evolution in(More)
By combining high-resolution transmission electron microscopy experiments and first-principles calculations, we study production, diffusion, and agglomeration of sulfur vacancies in monolayer MoS 2 under electron irradiation. Single vacancies are found to be mobile under the electron beam and tend to agglomerate into lines. Different kinds of such extended(More)