Dark-field transmission electron microscopy and the Debye-Waller factor of graphene

التفاصيل البيبلوغرافية
العنوان: Dark-field transmission electron microscopy and the Debye-Waller factor of graphene
المؤلفون: Shevitski, Brian, Mecklenburg, Matthew, Hubbard, William A., White, E. R., Dawson, Ben, Lodge, M. S., Ishigami, Masa, Regan, B. C.
المصدر: Phys. Rev. B 87 (2013) 045417
سنة النشر: 2012
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: Graphene's structure bears on both the material's electronic properties and fundamental questions about long range order in two-dimensional crystals. We present an analytic calculation of selected area electron diffraction from multi-layer graphene and compare it with data from samples prepared by chemical vapor deposition and mechanical exfoliation. A single layer scatters only 0.5% of the incident electrons, so this kinematical calculation can be considered reliable for five or fewer layers. Dark-field transmission electron micrographs of multi-layer graphene illustrate how knowledge of the diffraction peak intensities can be applied for rapid mapping of thickness, stacking, and grain boundaries. The diffraction peak intensities also depend on the mean-square displacement of atoms from their ideal lattice locations, which is parameterized by a Debye-Waller factor. We measure the Debye-Waller factor of a suspended monolayer of exfoliated graphene and find a result consistent with an estimate based on the Debye model. For laboratory-scale graphene samples, finite size effects are sufficient to stabilize the graphene lattice against melting, indicating that ripples in the third dimension are not necessary.
Comment: 10 pages, 4 figures
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevB.87.045417
URL الوصول: http://arxiv.org/abs/1207.0040
رقم الأكسشن: edsarx.1207.0040
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevB.87.045417