Fig. 4: Crystalline order of graphene papers.

a XRD profiles of GPs at a serials of SR. b FWHM of (002) peak in (a), showing gradually aligned and homogenized crystalline structure with SR increasing. c Schematic of the SAXS and WAXS tests, in which parallel section represents that X-ray is exposed on the section parallel to the stretching direction, perpendicular section represents that X-ray is exposed on the section perpendicular to the stretching direction. d Oriented structures of GPs in micro-scale (upper row, SEM images), nanoscale (middle row, SAXS patterns) and atomic scale (bottom row, WAXS patterns). Scale bar, 100 μm (d).