60 research outputs found

    Gold nanorods grown from HgTe nanoparticles directly on various surfaces

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    Gold nanorods (NRs) are nucleated by HgTe semiconductor nanoparticles. Growth of ~200 X 50 nm2 NRs directly on various surfaces is achieved by using an intermediary polyelectrolyte layer. X-ray photoelectron spectroscopy confirms the deposition of gold. An increase in the intensity of the Au NR plasmon resonance is observed with optical extinction spectroscopy. This seeding technique, amenable to many different surfaces, suggests a simple synthetic route to composite materials with interesting electronic and optical properties.Peer reviewedPhysicsChemistr

    Relaxation and reconstruction on (111) surfaces of Au, Pt, and Cu

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    We have theoretically studied the stability and reconstruction of (111) surfaces of Au, Pt, and Cu. We have calculated the surface energy, surface stress, interatomic force constants, and other relevant quantities by ab initio electronic structure calculations using the density functional theory (DFT), in a slab geometry with periodic boundary conditions. We have estimated the stability towards a quasi-one-dimensional reconstruction by using the calculated quantities as parameters in a one-dimensional Frenkel-Kontorova model. On all surfaces we have found an intrinsic tensile stress. This stress is large enough on Au and Pt surfaces to lead to a reconstruction in which a denser surface layer is formed, in agreement with experiment. The experimentally observed differences between the dense reconstruction pattern on Au(111) and a sparse structure of stripes on Pt(111) are attributed to the details of the interaction potential between the first layer of atoms and the substrate.Comment: 8 pages, 3 figures, submitted to Physical Review

    Burnt and Blossoming: Material Mysticism in Trilogy and Four Quartets

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    This paper brings two WWII poems into dialogue: H.D.'s Trilogy and Eliot's Four Quartets. Both poems express a creative response to the destruction of war. My reading of Trilogy suggests a material mysticism in which vision and renewal are situated within the natural world, rituals and bodily experience. Bringing this understanding of mysticism to bear on Four Quartets reveals tension between transcendence and materiality. For Eliot, redemption comes through time and location, while for H.D., redemption lies within material particularity. Four Quartets oscillates between an apophatic discourse that seeks to transcend desire and history and an emphasis on material particularities
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