Over the history of carbon, it is generally acknowledged that Bernal AB stacking of the sp 2 carbon layers is the unique crystalline form of graphite. The universal graphite structure is synthesized at 2,600∼3,000 °C and exhibits a micro-polycrystalline feature. In this paper, we provide evidence for a metastable form of graphite with an AA' structure. The non-Bernal AA' allotrope of graphite is synthesized by the thermal- and plasma-treatment of graphene nanopowders at ∼1,500 °C. The formation of AA' bilayer graphene nuclei facilitates the preferred texture growth and results in single-crystal AA' graphite in the form of nanoribbons (1D) or microplates (2D) of a few nm in thickness. Kinetically controlled AA' graphite exhibits unique nano- and single-crystalline feature and shows quasi-linear behavior near the K-point of the electronic band structure resulting in anomalous optical and acoustic phonon behavior.
Bibliographical noteFunding Information:
This work was supported by KIST Future Resource Program (V02120, 2E26390, 2E25404).
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