Nanomechanical cleavage of molybdenum disulphide atomic layers.
The discovery of two-dimensional materials became possible due to the mechanical cleavage technique. Despite its simplicity, the as-cleaved materials demonstrated surprising macro-continuity, high crystalline quality and extraordinary mechanical and electrical properties that triggered global research interest. Here such cleavage processes and associated mechanical behaviours are investigated by a direct in situ transmission electron microscopy probing technique, using atomically thin molybdenum disulphide layers as a model material. Our technique demonstrates layer number selective cleavage, from a monolayer to double layer and up to 23 atomic layers. In situ observations combined with molecular dynamics simulations reveal unique layer-dependent bending behaviours, from spontaneous rippling (<5 atomic layers) to homogeneous curving (~ 10 layers) and finally to kinking (20 or more layers), depending on the competition of strain energy and interfacial energy.
International Center for Young Scientists (ICYS), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 3050044, Japan.
Dai-Ming
DM
Tang
1] National University of Science and Technology MISiS, 4 Leninskiy prospekt, Moscow 119049, Russian Federation [2] Emanuel Institute of Biochemical Physics, 4 Kosigina Street, Moscow 119334, Russian Federation.
Dmitry G
DG
Kvashnin
Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
Sina
S
Najmaei
World Premier International (WPI) Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 3050044, Japan.
Yoshio
Y
Bando
Surface Physics and Structure Unit, National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 3050044, Japan.
Koji
K
Kimoto
NanoScience Center, Department of Physics, University of Jyväskylä, Jyväskylä FI-40014, Finland.
Pekka
P
Koskinen
Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
Pulickel M
PM
Ajayan
Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
Boris I
BI
Yakobson
1] National University of Science and Technology MISiS, 4 Leninskiy prospekt, Moscow 119049, Russian Federation [2] Emanuel Institute of Biochemical Physics, 4 Kosigina Street, Moscow 119334, Russian Federation [3] Technological Institute of Superhard and Novel Carbon Materials, 7a Centralnaya Street, Troitsk, Moscow 142190, Russian Federation.
Pavel B
PB
Sorokin
Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
Jun
J
Lou
World Premier International (WPI) Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 3050044, Japan.
Dmitri
D
Golberg