Search results for "scanning probe"

Probing large area surface plasmon interference in thin metal films using photon scanning tunneling microscopy.

2003

Abstract The interference of surface plasmons can provide important information regarding the surface features of the hosting thin metal film. We present an investigation of the interference of optically excited surface plasmons in the Kretschmann configuration in the visible spectrum. Large area surface plasmon interference regions are generated at several wavelengths and imaged with the photon scanning tunneling microscope. Furthermore, we discuss the non-retarded dispersion relations for the surface plasmons in the probe–metal system modeled as confocal hyperboloids of revolution in the spheroidal coordinate systems.

Curvature effects in surface plasmon dispersion and coupling

2005

We have studied the resonant coupling of surface plasmons in curved thin-film tunneling geometries by obtaining the dispersion relations for the system. The surface plasmon dispersion relations are calculated for a metal-coated dielectric probe above a dielectric half space with and without metal coating. The system is modeled in the prolate spheroidal system, and the dispersion relations are studied as functions of the parameter that defines the boundaries of the tip and the corresponding coating, and as functions of the involved coating thicknesses. Using this type of probe-substrate configuration, the nonradiative surface plasmon coupling mechanism is investigated in the visible spectrum…

Individual arc-discharge synthesized multiwalled carbon nanotubes probed with multiple measurement techniques

2020

Arc-discharge synthesized multiwalled carbon nanotubes (AD-MWNT), or related MWNTs, exhibit a good quality compared to the more common type of MWNT synthesized by catalytic chemical vapor deposition methods. Yet experimental measurements on these are rather few and typically have not correlated data from different measurement techniques. Here, the authors report Raman spectroscopy, scanning probe microscopy, conductivity measurements, and force microscopy on single AD-MWNTs. The results demonstrate the high quality of AD-MWNTs and are compatible with the view of them as the best approximation of MWNTs as an assembly of defect-free concentric individual single-walled carbon nanotubes. The au…

Hockey-Puck micelles from oligo(p-benzamide)-b-PEG rod-coil block copolymers.

2006

Temperature and pressure dependence of quercetin-3-O-palmitate interaction with a model phospholipid membrane: film balance and scanning probe micros…

2004

The molecular interaction of quercetin-3-O-palmitate (QP) with dimyristoylphosphatidylcholine (DMPC) has been studied. Film balance measurements of the average molecular area vs QP molar fraction in DMPC/QP mixed monolayers showed that relevant positive deviations from ideality, i.e., a less dense monolayer packing, occurred for a temperature of 10 degrees C, below the critical melting transition temperature of DMPC monolayers T c m approximately equal 20 degrees C), while ideal behavior was observed at 37 degrees C, above this phase transition temperature. The positive deviation observed at low temperatures in the average molecular area increased with the surface pressure. Scanning probe m…

ChemInform Abstract: Scanning Probe Microscopy Study of the Metal-Rich Layered Chalcogenides TaM2Te2 (M: Co, Ni).

2010

Super-Resolution Scanning Near-Field Optical Microscopy

2007

Scanning near-field optical microscopy (SNOM) is a method to obtain information about the optical properties of a sample at a lateral resolution below the diffraction limit of far-field microscopy. In SNOM, a light source of a dimension which is small compared to the wavelength of light and which is held at a small distance from the sample is scanned across the surface of the sample. The modulation by the sample of the light emitted from the source is recorded as a signal. As a general rule one may say that the size of the source and the distance to the sample limit the resolution of SNOM. A radiating self-emitting point dipole may be regarded as an idealized SNOM source. With such a source…

First images obtained in the near infrared spectrum with the photon scanning tunneling microscope

1993

Abstract First images obtained in the near infrared spectrum with a photon scanning tunneling microscope are presented. The intensity of the light collected by the fibertip, at λ = 1.3 λm , which is a function of the separation between the tip and the sample surface is in agreement with that predicted by the theory. Images of quartz and silicon oxide are presented and the latter is compared with that obtained by an atomic force microscope.

Benzo-Fused Periacenes or Double Helicenes? Different Cyclodehydrogenation Pathways on Surface and in Solution

2019

Controlling the regioselectivity of C-H activation in unimolecular reactions is of great significance for the rational synthesis of functional graphene nanostructures, which are called nanographenes. Here, we demonstrate that the adsorption of tetranaphthyl- p-terphenyl precursors on metal surfaces can completely change the cyclodehydrogenation route and lead to obtaining planar benzo-fused perihexacenes rather than double [7]helicenes during solution synthesis. The course of the on-surface planarization reactions is monitored using scanning probe microscopy, which unambiguously reveals the formation of dibenzoperihexacenes and the structures of reaction intermediates. The regioselective pl…

Flexible drift-compensation system for precise 3D force mapping in severe drift environments

2011

The acquisition of dense 3D data sets is of great importance, but also a challenge for scanning probe microscopy (SPM). Thermal drift often induces severe distortions in the data, which usually constrains the acquisition of dense data sets to experiments under ultra-high vacuum and low-temperature conditions. Atom tracking is an elegant approach to compensate for thermal drift and to position the microscope tip with highest precision. Here, we present a flexible drift compensation system which can easily be connected to existing SPM hardware. Furthermore, we describe a 3D data acquisition and position correction protocol, which is capable of handling large and non-linear drift as typically …