TY - JOUR
T1 - In situ observation of stress relaxation in epitaxial graphene
AU - N'diaye, Alpha T.
AU - van Gastel, Raoul
AU - Martínez-Galera, Antonio J.
AU - Coraux, Johann
AU - Hattab, Hichem
AU - Wall, Dirk
AU - Meyer zu Heringdorf, Frank-J.
AU - Horn von Hoegen, Michael
AU - Gómez-Rodríguez, José M.
AU - Poelsema, Bene
AU - Busse, Carsten
AU - Michely, Thomas
PY - 2009
Y1 - 2009
N2 - Upon cooling, branched line defects develop in epitaxial graphene grown at high temperature on Pt(111) and Ir(111). Using atomically resolved scanning tunneling microscopy, we demonstrate that these defects are wrinkles in the graphene layer, i.e. stripes of partially delaminated graphene. With low energy electron microscopy (LEEM), we investigate the wrinkling phenomenon in situ. Upon temperature cycling, we observe hysteresis in the appearance and disappearance of the wrinkles. Simultaneously with wrinkle formation a change in bright field imaging intensity of adjacent areas and a shift in the moiré spot positions for micro diffraction of such areas takes place. The stress relieved by wrinkle formation results from the mismatch in thermal expansion coefficients of graphene and the substrate. A simple one-dimensional model taking into account the energies related to strain, delamination and bending of graphene is in qualitative agreement with our observations.
AB - Upon cooling, branched line defects develop in epitaxial graphene grown at high temperature on Pt(111) and Ir(111). Using atomically resolved scanning tunneling microscopy, we demonstrate that these defects are wrinkles in the graphene layer, i.e. stripes of partially delaminated graphene. With low energy electron microscopy (LEEM), we investigate the wrinkling phenomenon in situ. Upon temperature cycling, we observe hysteresis in the appearance and disappearance of the wrinkles. Simultaneously with wrinkle formation a change in bright field imaging intensity of adjacent areas and a shift in the moiré spot positions for micro diffraction of such areas takes place. The stress relieved by wrinkle formation results from the mismatch in thermal expansion coefficients of graphene and the substrate. A simple one-dimensional model taking into account the energies related to strain, delamination and bending of graphene is in qualitative agreement with our observations.
KW - METIS-262655
U2 - 10.1088/1367-2630/11/11/113056/meta
DO - 10.1088/1367-2630/11/11/113056/meta
M3 - Article
SN - 1367-2630
VL - 11
JO - New journal of physics
JF - New journal of physics
IS - 11
M1 - 113056
ER -