Local anodic oxidation (LAO) has been performed on highly oriented pyrolytic graphite (HOPG) and few layer graphene (FLG) using contact-mode (CM) atomic force microscopy (AFM) in a controlled humidity chamber. Different types of LAO patterns, namely, protrusion and trench features were observed for different tip speeds under similar conditions of LAO patterning, in both CM and noncontact-mode (NCM) AFM images. Observed LAO patterns show a variation in their dimensions over time. This paper carries out a study performed on the observed changes in dimensions of LAO patterns made on HOPG and FLG over several days, pointing to the dynamics of these LAO patterns. The stability of the LAO patterns on HOPG is compared with that for FLG. LAO patterns on HOPG show a widening and reduction in depth over a day. LAO patterns on FLG show, in contrast, a random variation in the lateral dimension "width" and stabilization in the vertical dimension "depth" over several days. © 2002-2012 IEEE.

Gargi Raina

Electronics

School of Electronics Engineering

Chennai Campus

Gowthami T

Gadhewal M

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

Study of Stability of Local Anodic Oxidation on HOPG and Few Layer Graphene Using AFM in Ambient

IEEE Transactions on Nanotechnology

In this work, we report the impact of the interaction and dynamics of increasing ambient water adlayers on etch patterns on a hydrophobic highly oriented pyrolytic graphite (HOPG) surface obtained using atomic force microscopy (AFM) voltage nanolithography in contact mode by applying a positive bias to the sample. The changes in the dimensions of the etch patterns were investigated as a function of the increasing number of water adlayers present on the HOPG, which is varied by changing the time interval since HOPG cleavage. Changes in the width of the etch patterns and the surrounding water droplets were monitored with time, using intermittent-contact-mode AFM. Electrostatic force microscopy (EFM) has been employed to study the charged nature of the etch patterns and the neighboring water film with time. The width of the etch patterns made on freshly cleaved HOPG shows an increase of ∼33% over 48 h, whereas nine-day-old cleaved HOPG shows a 79% increase over the same period. No changes in the dimensions are observed while imaging in a nitrogen atmosphere soon after lithography. In ambient conditions, the EFM phase shift of the patterns shows a large change of ∼84-88% over 30 h. This study demonstrates the effect of the stored electrostatic energy of a polarized ice-like water adlayer, resulting in changes in the dimensions of the etch patterns long after lithography, whereas liquid-like water droplets do not affect the etch patterns. © 2014 IOP Publishing Ltd.

Nanotechnology

Interaction and dynamics of ambient water adlayers on graphite probed using AFM voltage nanolithography and electrostatic force microscopy

Journal of Chemical Sciences

Synthesis, photophysical, electrochemical and electroluminescence studies of red emitting phosphorescent Ir(III) heteroleptic complexes

Nanoscale Research Letters

A novel mechanical cleavage method for synthesizing few-layer graphenes

ACS Nano

Nanoscale Lithography on Monolayer Graphene Using Hydrogenation and Oxidation

Graphite patterning in a controlled gas environment

Charge storage in mesoscopic graphitic islands fabricated using AFM bias lithography

Journal	Data powered by TypesetIEEE Transactions on Nanotechnology
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers (IEEE)
ISSN	1536-125X
Open Access	0