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Huth F.,CIC Nanogune | Huth F.,Neaspec GmbH | Govyadinov A.,CIC Nanogune | Amarie S.,Max Planck Institute of Quantum Optics | And 4 more authors.
Nano Letters | Year: 2012

We demonstrate Fourier transform infrared nanospectroscopy (nano-FTIR) based on a scattering-type scanning near-field optical microscope (s-SNOM) equipped with a coherent-continuum infrared light source. We show that the method can straightforwardly determine the infrared absorption spectrum of organic samples with a spatial resolution of 20 nm, corresponding to a probed volume as small as 10 zeptoliter (10 -20 L). Corroborated by theory, the nano-FTIR absorption spectra correlate well with conventional FTIR absorption spectra, as experimentally demonstrated with poly(methyl methacrylate) (PMMA) samples. Nano-FTIR can thus make use of standard infrared databases of molecular vibrations to identify organic materials in ultrasmall quantities and at ultrahigh spatial resolution. As an application example we demonstrate the identification of a nanoscale PDMS contamination on a PMMA sample. © 2012 American Chemical Society.

Johnson C.M.,KTH Royal Institute of Technology | Bohmlerb M.,Neaspec GmbH
Corrosion Science | Year: 2016

Since corrosion commonly occurs heterogeneously over a surface, studies on a microscopic level are desired to obtain a complete picture of the process. Here, we demonstrate the capability of nano-FTIR microscopy to spectroscopically determine the nature of different corrosion products and their spatial distribution with a resolution of 20. nm, two-three orders of magnitude better than conventional IR microscopy. A copper surface was exposed to a humid atmosphere containing formic acid, and in addition to cuprite the corrosion product copper formate was observed to form inhomogeneously in particles of some tens to a few hundreds of nm. © 2016 Elsevier Ltd.

Hermann P.,Physikalisch - Technische Bundesanstalt | Hoehl A.,Physikalisch - Technische Bundesanstalt | Patoka P.,Free University of Berlin | Huth F.,Neaspec GmbH | And 2 more authors.
Optics Express | Year: 2013

We demonstrate scanning near-field optical microscopy with a spatial resolution below 100 nm by using low intensity broadband synchrotron radiation in the IR regime. The use of such a broadband radiation source opens up the possibility to perform nano-Fourier-transform infrared spectroscopy over a wide spectral range. © 2013 Optical Society of America.

Stiegler J.M.,CIC Nanogune | Huber A.J.,Neaspec GmbH | Diedenhofen S.L.,Philips | Gomez Rivas J.,Philips | And 6 more authors.
Nano Letters | Year: 2010

We report quantitative, noninvasive and nanoscale-resolved mapping of the free-carrier distribution in InP nanowires with doping modulation along the axial and radial directions, by employing infrared near-field nanoscopy. Owing to the technique's capability of subsurface probing, we provide direct experimental evidence that dopants in interior nanowire shells effectively contribute to the local free-carrier concentration. The high sensitivity of s-SNOM also allows us to directly visualize nanoscale variations in the free-carrier concentration of wires as thin as 20 nm, which we attribute to local growth defects. Our results open interesting avenues for studying local conductivity in complex nanowire heterostructures, which could be further enhanced by near-field infrared nanotomography. © 2010 American Chemical Society.

Govyadinov A.A.,CIC Nanogune | Amenabar I.,CIC Nanogune | Huth F.,CIC Nanogune | Huth F.,Neaspec GmbH | And 3 more authors.
Journal of Physical Chemistry Letters | Year: 2013

Scattering-type scanning near-field optical microscopy (s-SNOM) and Fourier transform infrared nanospectroscopy (nano-FTIR) are emerging tools for nanoscale chemical material identification. Here, we push s-SNOM and nano-FTIR one important step further by enabling them to quantitatively measure local dielectric constants and infrared absorption. Our technique is based on an analytical model, which allows for a simple inversion of the near-field scattering problem. It yields the dielectric permittivity and absorption of samples with 2 orders of magnitude improved spatial resolution compared to far-field measurements and is applicable to a large class of samples including polymers and biological matter. We verify the capabilities by determining the local dielectric permittivity of a PMMA film from nano-FTIR measurements, which is in excellent agreement with far-field ellipsometric data. We further obtain local infrared absorption spectra with unprecedented accuracy in peak position and shape, which is the key to quantitative chemometrics on the nanometer scale. © 2013 American Chemical Society.

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