Search results for "Photoconductive atomic force microscopy"
showing 7 items of 7 documents
Investigation of TiO<sub>2</sub> Ceramic Surface Conductivity Using Conductive Atomic Force Microscopy
2012
Dense TiO2 (rutile) ceramic samples were prepared by sintering compacts of titanium dioxide anatase powder at 1500 °C for 5h. Sintered samples were polished and annealed in vacuum at 1000 °C for 1h. Structural properties of the samples were studied by X-ray diffraction, polarized light and scanning electron microscopy. The surface topography and local electrical conductivity of the samples were investigated by atomic force microscopy technique under atmospheric conditions. Enhanced electrical conductivity was observed at grain boundaries while the polished, vacuum annealed grains surface showed non-homogeneous conductivity.
Correlative atomic force and confocal fluorescence microscopy: single molecule imaging and force induced spectral shifts (Conference Presentation)
2016
A grand challenge in nanoscience is to correlate structure or morphology of individual nano-sized objects with their photo-physical properties. An early example have been measurements of the emission spectra and polarization of single semiconductor quantum dots as well as their crystallographic structure by a combination of confocal fluorescence microscopy and transmission electron microscopy.[1] Recently, the simultaneous use of confocal fluorescence and atomic force microscopy (AFM) has allowed for correlating the morphology/conformation of individual nanoparticle oligomers or molecules with their photo-physics.[2, 3] In particular, we have employed the tip of an AFM cantilever to apply c…
Micro-Raman characterization of graphene grown on SiC(000-1)
2014
Graphene (Gr) was grown on the C face of 4H-SiC under optimized conditions (high annealing temperatures ranging from 1850 to 1950°C in Ar ambient at 900 mbar) in order to achieve few layers of Gr coverage. Several microscopy techniques, including optical microscopy (OM), ?Raman spectroscopy, atomic force microscopy (AFM) and atomic resolution scanning transmission electron microscopy (STEM) have been used to extensively characterize the lateral uniformity of the as-grown layers at different temperatures. ?Raman analysis provided information on the variation of the number of layers, of the stacking-type, doping and strain.
Single-molecule switching with non-contact atomic force microscopy
2011
We report upon controlled switching of a single 3,4,9,10-perylene tetracarboxylic diimide derivative molecule on a rutile TiO(2)(110) surface using a non-contact atomic force microscope at room temperature. After submonolayer deposition, the molecules adsorb tilted on the bridging oxygen row. Individual molecules can be manipulated by the atomic force microscope tip in a well-controlled manner. The molecules are switched from one side of the row to the other using a simple approach, taking benefit of the sample tilt and the topography of the titania substrate. From density functional theory investigations we obtain the adsorption energies of different positions of the molecule. These adsorp…
Assessment of Polarity in GaN Self-Assembled Nanowires by Electrical Force Microscopy
2015
In this work, we demonstrate the capabilities of atomic force microscopies (AFMs) for the nondestructive determination of the polarity of GaN nanowires (NWs). Three complementary AFMs are analyzed here: Kelvin probe force microscopy (KPFM), light-assisted KPFM, and piezo-force microscopy (PFM). These techniques allow us to assess the polarity of individual NWs over an area of tens of μm(2) and provide statistics on the polarity of the ensemble with an accuracy hardly reachable by other methods. The precise quantitative analysis of the tip-sample interaction by multidimensional spectroscopic measurements, combined with advanced data analysis, has allowed the separate characterization of elec…
Second-harmonic Generation Microscopy of Carbon Nanotubes
2012
We image an individual single-walled carbon nanotube (SWNT) by second-harmonic generation (SHG) and transmission electron microscopy and propose that SHG microscopy could be used to probe the handedness of chiral SWNTs.
<title>Scanning probe microscopy of nanocrystalline iridium oxide thin films</title>
2003
Structural investigations of nanocrystalline iridium oxide thin films, prepared by dc magnetron sputtering technique were performed by scanning probe microscopy (SPM). SPM studies, using both atomic force microscopy (AFM) and scanning tunnelling microscopy (STM), indicate that the thin films are composed of grains with a size of about 20-50 nm. Fine crystallinity and small RMS microroughness of the films, being well below 2 nm, make iridium oxide thin films promising candidates for nanolithographic applications. The possibility to perform nanolithograhpic processes at a scale of less than 150 nm was successfully examined in AFM and STM modes.© (2003) COPYRIGHT SPIE--The International Societ…