“Surface Phonon Polaritons helping in the lab: infrared synchrotron radiation sweeping surfaces and nanostructures”

Infrared radiation is widely used to identify substances. For example, a molecule with different vibrational modes will produce a very characteristic pattern in an infrared spectrum, allowing its identification even if the molecule is only part of a complex mixture of substances. This strategy is used in astrophysical identification of which molecules are present in a selected region of space. At a nanometer observational scale, however, this strategy becomes significantly complicated by the diffraction limit, which blurs images of nanometer-sized objects in the infrared, if conventional optical microscopy techniques are used. This colloquium will discuss an experimental approach capable of beating the diffraction limit for the infrared, combining nanometer-scale topographic information and spectroscopic information. It is based on the combination of conventional atomic force microscopy (AFM) with the scattering of infrared radiation simultaneously by the microscope tip and by the sample being studied. Using a synchrotron radiation source to generate the infrared incident beam expands the accessible frequency range compared to infrared lasers. In this technique, the production and detection of Surface Phonon Polaritons is key to enabling infrared studies by isolating a surface layer of a sample [1] or even a nanostructure [2], and will be discussed in the colloquium.

References:

[1]-“Tailoring Surface Phonon Polariton on SiO2 by Ion-Beam Irradiation”, C.F.S. Codeço, S.L.A. Mello, G.M. Penello, B.F. Magnani, A.C.F. Santos, and M.M. Sant’Anna, J. Phys. Chem. C 128, (2024) 18566.

[2] “Superficial Si nanostructure synthesis by low-energy ion-beam-induced phase separation”,  C.F.S. Codeço, I.D. Barcelos, S.L.A. Mello, G.M. Penello, B.F. Magnani, A.C.F. Santos, and M. M. Sant’Anna, Applied Surface Science 601 (2022) 154190.

Transmisión en vivo vía bit.ly/YouTube_ICF

Participante: Dr. Marcelo M. Sant'Anna

Institución: Instituto de Física de la Universidad Federal de Río de Janeiro, Brasil

Fecha y hora: Miércoles, 29 de Octubre de 2025 a las 12:00