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Graphene is a kind of typical two-dimensional material consisting of pure carbon element. The unique material shows many interesting properties which are dependent on crystallographic orientations. Therefore, it is critical to determine their crystallographic orientations when their orientation-dependent properties are investigated. Raman spectroscopy has been developed recently to determine crystallographic orientations of two-dimensional materials and has become one of the most powerful tools to characterize graphene nondestructively. This paper summarizes basic aspects of Raman spectroscopy in crystallographic orientation of graphene nanosheets, determination principles, the determination methods, and the latest achievements in the related studies.

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Boron carbide has been widely utilized in industry and military because of its low mass-density, superhigh hardness and good electric conductivity [1,2]. It is predicted that its excellent mechanical properties can be enhanced in nanomaterials [3]. The material is also one kind of thermoelectric compound working at high temperatures above 1000 o C [4]. However, its thermoelectric properties, such as Seebeck coefficient and figure-of-merit, are low and need to be enhanced significantly for potential applications. Nanostructuring is an effective approach to improve thermoelectric properties [5] and boron carbide nanocomposites with high performances can be bottom-up-ed from nanomaterials by the approach. So boron carbide nanomaterials play a key role as starting materials of the carbide nanocomposites. Here, carbon-rich boron carbide nanomaterials are synthesized and characterized by electron energy-loss spectroscopy (EELS) on transmission electron microscope (TEM).

Boron monoarsenide (BAs), one III-V compound synthesized and grown since the 1960s [1-4], has been long-time ignored since its discovery. The unpopular material revokes scientists interesting recently because of its potentially high thermal conductivity [5-7], good photoelectric properties [8], and decent thermoelectric characteristic [9]. Single crystal X-ray diffraction [5] and powder X-ray diffraction [1,10] indicated that the space group of BAs should be F 3m with the zinc-blende structure at room temperature, similar as other III-V arsenides and boron compounds. Here, the space group of the compound is confirmed by convergent beam electron diffraction (CBED).