TY - JOUR
T1 - Unusual Moiré superlattices in exfoliated μm-thin HOPG lamellae
T2 - An angular-diffraction study
AU - Boi, Filippo S.
AU - Shuai, Gao
AU - Wen, Jiqiu
AU - Wang, Shanling
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/10
Y1 - 2020/10
N2 - The observation of intrinsic magnetic correlation phenomena in presence of Moiré-superlattices in twisted-bilayer-graphene, double-bilayer-graphene and graphite has recently attracted important attention. By employing high resolution transmission electron microscopy (HRTEM), in this study we have investigated μm-thin HOPG-lamellae with unusual Moiré-superlattices. Anomalous large periodicities of ~80 nm and ~40 nm, possibly corresponding to θmisfit of 0.18° and 0.35° are reported. X-ray-rocking-curve-analyses, evidenced the presence of non-monotonic signals, a clear indicator of dislocation-rich-properties. Selective area electron diffraction (SAED) of the superlattice further revealed the presence of anomalous doubled diffraction patterns. The angular-dependence of SAED with sample-tilt from 0° to 0.93° evidenced an increase in the pattern-intensity up to a maximum for sample-tilt of 0.33°. Disappearance (of SAED-doubled-pattern and Moiré-superlattice) was found for 0.66° and 0.93° tilt. Re-appearance was further verified, by taking the sample back to 0.33° tilt. Raman-spectroscopy and scanning electron microscopy supported the observed results, revealing 1) presence of D and D’ band signals and 2) absence of sample oxidation.
AB - The observation of intrinsic magnetic correlation phenomena in presence of Moiré-superlattices in twisted-bilayer-graphene, double-bilayer-graphene and graphite has recently attracted important attention. By employing high resolution transmission electron microscopy (HRTEM), in this study we have investigated μm-thin HOPG-lamellae with unusual Moiré-superlattices. Anomalous large periodicities of ~80 nm and ~40 nm, possibly corresponding to θmisfit of 0.18° and 0.35° are reported. X-ray-rocking-curve-analyses, evidenced the presence of non-monotonic signals, a clear indicator of dislocation-rich-properties. Selective area electron diffraction (SAED) of the superlattice further revealed the presence of anomalous doubled diffraction patterns. The angular-dependence of SAED with sample-tilt from 0° to 0.93° evidenced an increase in the pattern-intensity up to a maximum for sample-tilt of 0.33°. Disappearance (of SAED-doubled-pattern and Moiré-superlattice) was found for 0.66° and 0.93° tilt. Re-appearance was further verified, by taking the sample back to 0.33° tilt. Raman-spectroscopy and scanning electron microscopy supported the observed results, revealing 1) presence of D and D’ band signals and 2) absence of sample oxidation.
UR - http://www.scopus.com/inward/record.url?scp=85096856483&partnerID=8YFLogxK
U2 - 10.1016/j.diamond.2020.107920
DO - 10.1016/j.diamond.2020.107920
M3 - Article
AN - SCOPUS:85096856483
SN - 0925-9635
VL - 108
JO - Diamond and Related Materials
JF - Diamond and Related Materials
M1 - 107920
ER -