Scanning Tunneling Microscopy Study and Nanomanipulation of Graphene-Coated Water on Mica

We study interfacial water trapped between a sheet of graphene and a muscovite (mica) surface using Raman spectroscopy and ultra-high vacuum scanning tunneling microscopy (UHV-STM) at room temperature. We are able to image the graphene-water interface with atomic resolution, revealing a layered network of water trapped underneath the graphene. We identify water layer numbers with a carbon nanotube height reference. Under normal scanning conditions, the water structures remain stable. However, at greater electron energies, we are able to locally manipulate the water using the STM tip.Comment: In press, 5 figures, supplementary information at Nano Letters websit

Relative equity market valuation conditions and acquirers’ gains

We examine whether the relative equity market valuation conditions (EMVCs) in the merging firms countries help acquirers’ managers to time the announcements of domestic and foreign target acquisitions. After controlling for several deal- and merging firms-specific features we find that acquisition activity, as well as acquirers gains, are significantly higher during periods of high-EMVCs at home, irrespective of the domicile of the target. We also find that the higher foreign acquirers’ gains that reaped during periods of high-EMVCs at home are realized by deals of targets based in the RoW (=World-G7), rather than G6 (=G7-UK) countries, which is due to the low correlation of EMVCs between the U.K. (home) and the RoW countries. Moreover, acquisition of targets domiciled in the RoW (G6) countries yield higher (lower) gains than domestic targets during periods of high-EMVCs at home. This suggests that the relative EMVCs between the merging firms’ countries allow acquirers’ managers to time the market and acquire targets at a discount, particularly in countries in which acquirers’ stocks are likely to be more overvalued than the targets’ stocks

Scanning Tunneling Microscopy Study and Nanomanipulation of Graphene-Coated Water on Mica

We study interfacial water trapped between a sheet of graphene and a muscovite (mica) surface using Raman spectroscopy and ultrahigh vacuum scanning tunneling microscopy (UHV-STM) at room temperature. We are able to image the graphene–water interface with atomic resolution, revealing a layered network of water trapped underneath the graphene. We identify water layer numbers with a carbon nanotube height reference. Under normal scanning conditions, the water structures remain stable. However, at greater electron energies, we are able to locally manipulate the water using the STM tip

Graphene-Based Platform for Infrared Near-Field Nanospectroscopy of Water and Biological Materials in an Aqueous Environment

Scattering scanning near-field optical microscopy (s-SNOM) has emerged as a powerful nanoscale spectroscopic tool capable of characterizing individual biomacromolecules and molecular materials. However, applications of scattering-based near-field techniques in the infrared (IR) to native biosystems still await a solution of how to implement the required aqueous environment. In this work, we demonstrate an IR-compatible liquid cell architecture that enables near-field imaging and nanospectroscopy by taking advantage of the unique properties of graphene. Large-area graphene acts as an impermeable monolayer barrier that allows for nano-IR inspection of underlying molecular materials in liquid. Here, we use s-SNOM to investigate the tobacco mosaic virus (TMV) in water underneath graphene. We resolve individual virus particles and register the amide I and II bands of TMV at <i>ca</i>. 1520 and 1660 cm^–1, respectively, using nanoscale Fourier transform infrared spectroscopy (nano-FTIR). We verify the presence of water in the graphene liquid cell by identifying a spectral feature associated with water absorption at 1610 cm^–1