Cu Intercalation under a Zero Layer Graphene Grown on a SiC(0001) Surface

AbstractCoulomb drag in double layer graphene systems separated by an h-BN interlayer allows probing of the electron-electron interactions in the effective limit of zero layer separation. Although these interactions can be influenced by plasmons, phonons and exchange and correlation effects, these excitations have never been studied altogether, missing the effects of their coupling on the drag physics. Here we study theoretically the effects of these quasiparticles and their coupling, including also the effects of the electronic exchange and correlation, and demonstrate that the drag resistivity can attain a maximum value at room temperature and beyond, where hybridized plasmon-phonon modes contribute significantly. In particular, the hybridization of the plasmons with the hyperbolic phonons of h-BN, confined within the reststrahlen bands, enhance the drag resistivity. This study paves the way for the exploration of novel many-body physics phenomena in systems coupled through emerging 2D hyperbolic materials.

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Convergent Beam Electron Diffraction Zone Axis Pattern Map of Zirconium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136088 ◽

1990 ◽

Vol 48 (2) ◽

pp. 496-497

Author(s):

E. Silva ◽

R. Scozia

Keyword(s):

Electron Diffraction ◽

Convergent Beam Electron Diffraction ◽

Zone Axis ◽

Pole Piece ◽

Small Particles ◽

Present Communication ◽

Beam Electron ◽

Zero Layer ◽

Set Up ◽

Convergent Beam

The purpose in obtaining zone axis pattern map (zap map) from a given material is to provide a quick and reliable tool to identify cristaline phases, and crystallographic directions, even in small particles. Bend contours patterns and Kossel lines patterns maps from Zr single crystal in the [0001] direction have been presented previously. In the present communication convergent beam electron diffraction (CBED) zap map of Zr will be shown. CBED patterns were obtained using a Philips microscope model EM300, which was set up to carry out this technique. Convergent objective upper pole piece for STEM and some electronic modifications in the lens circuits were required, furthermore the microscope was carefully cleaned and it was operated at a vacuum eminently good.CBED patterns in the Zr zap map consist of zero layer disks, showing fine details within them which correspond to intersecting set of higher order Laue zone (HOLZ) deficiency lines.

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Microtwinning Evidence For The Apparent Five-Fold Symmetry in T2(Al6Li3Cu)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125178 ◽

1987 ◽

Vol 45 ◽

pp. 24-25

Author(s):

Kenneth S. Vecchio ◽

David B. Williams

Keyword(s):

Stable Equilibrium ◽

Equilibrium Phase ◽

Convergent Beam Electron Diffraction ◽

Icosahedral Structure ◽

Cubic Crystals ◽

Icosahedral Phases ◽

Heat Treated ◽

Zero Layer ◽

Convergent Beam ◽

Zr Alloy

Since the discovery in 1984 by Shechtman et al. of crystals which display apparent five-fold symmetry, extensive effort has been given to establishing a theoretical basis for the existence of icosahedral phases (eg.2.). Several other investigations have been centered on explaining these observations based on twinning of cubic crystals (eg.3.). Recently, the existence of a stable, equilibrium phase T2Al6 Li3Cu) possessing an icosahedral structure has been reported in the Al-Li-Cu system(4-6).In the present study an Al-2.6wt.%Li-l.5wt.%Cu-0.lwt.%Zr alloy was heat treated at 300°C for 100hrs. to produce large T2 precipitates. Convergent Beam Electron Diffraction (CBED) patterns were obtained from two-fold, three-fold, and apparent five-fold axes of T2 particles. Figure 1 shows the five-fold symmetric zero layer CBED pattern obtained from T2 particles.

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