01698nas a2200157   4500008004100000245007200041210006900113260000800182300001000190490001100200520116500211100001801376700001901394700002201413856010501435       2017                        eng d00aRevisiting HOPG superlattices: structure and conductance properties0 aRevisiting HOPG superlattices structure and conductance properti  cAPR  a55-600 v 658  3 aSuperlattices observed on highly oriented pyrolytic graphite (HOPG) have been studied extensively by scanning tunnelling microscopy (STM). The interest in the study of graphite superlattices has seen a resurgence since the discovery of graphene. Single layer graphene, bilayer graphene, and few layer graphene can now be grown on different substrates. The adherence of graphene to various substrates often leads to a periodic out-of-plane modulation and superlattices due to lattice mismatch. In this paper, we report STM imaging and scanning tunnelling spectroscopy (STS) of different kinds of superlattices on HOPG characterized by a variation in lattice periodicities. Our study also shows evidence of the displacement of the topmost HOPG layer by scanning different areas of the same superlattice. A correlation between the lattice periodicity with its conductance properties is derived. The results of this work are important for understanding the origin of the superlattice structure on HOPG. Investigation of such superlattices may open up possible ways to modify two dimensional electron systems to create materials with tailored electronic properties.1 aPatil, Sumati1 aKolekar, Sadhu1 aDeshpande, Aparna  uhttp://library.ncl.res.in/content/revisiting-hopg-superlattices-structure-and-conductance-properties02523nas a2200253   4500008004100000022001400041245009000055210006900145260000800214300001400222490000700236520166400243653003001907653002901937653003401966653003602000100001802036700001902054700001802073700002502091700001902116700002602135856010802161       2018                        eng d  a1533-488000aInvestigation of disorder in mixed phase, sp(2)-sp(3) bonded graphene-like nanocarbon0 aInvestigation of disorder in mixed phase sp2sp3 bonded graphenel  cAPR  a2504-25120 v183 a<p>Disorder in a mixed phase, sp(2)-sp(3) bonded graphene-like nanocarbon (GNC) lattice has been extensively studied for its electronic and field emission properties. Morphological investigations are performed using scanning electron microscopy (SEM) which depicts microstructures comprising of atomically flat terraces (c-planes) with an abundance of edges (ab planes which are orthogonal to c-planes). Scanning tunneling microscopy (STM) is used to observe the atomic structure of basal planes whereas field emission microscopy (FEM) is found to be suitable for resolving nanotopography of edges. STM images revealed the hexagonal and non-hexagonal atomic arrangements in addition to a variety of defect structures. Scanning tunneling spectroscopy is carried out to study the effect of this short-range disorder on the local density of states. Current versus voltage (I-V) characteristics have been recorded at different defect sites and are compared with respect to the extent of the defect. As sharp edges of GNC are expected to be excellent field emitters, because of low work function and high electric field, enhancement in current is observed particularly when applied electric field is along basal planes. Therefore, it is worthwhile to investigate field emission from these samples. The FEM images show a cluster of bright spots at low voltages which later transformed into an array resembling ledges of ab-planes with increasing voltage. Reproducible I-V curves yield linear Fowler-Nordheim plots supporting field emission as the dominant mechanism of electron emission. Turn on field for 10 mu A current is estimated to be similar to 3 V/mu m.</p>10aField emission microscopy10aGraphene-Like Nanocarbon10aScanning tunneling microscopy10aScanning Tunneling Spectroscopy1 aPatil, Sumati1 aKolekar, Sadhu1 aKumar, Arvind1 aAlegaonkar, Prashant1 aDatar, Suwarna1 aDharmadhikari, C., V.  uhttp://library.ncl.res.in/content/investigation-disorder-mixed-phase-sp2-sp3-bonded-graphene-nanocarbon