Article Dans Une Revue Brazilian Journal of Physics Année : 2024

Dielectric Function of Oriented Hollow Vegetal Fibers Retrieved from XPS, Diffuse Reflection, and Photoacoustic Spectroscopies

Résumé

Diffuse reflectance spectroscopy (DRS) and photoacoustic absorption spectroscopy (PAS) are investigated in model systems that mimic topological structures found in vegetal fibers, e.g. made of oriented hollow channels. Among this wide family, the shiny optical aspect of Golden grass stems has motivated detailed investigations of their chemical composition, microstructure and electronic properties. In this work, diffuse reflectance and absorption of a photon flux within a collection of parallel hollow fibers are addressed using 2D optical models, neglecting interface scattering. Analytical results obtained for hollow square tube (HST) and plane parallel membrane (PPM) arrays are validated by full ray-tracing calculations. Optical paths with multiple reflection / refraction events at air-fiber interfaces selectively enhance DRS and PAS intensities and thus explain the shiny golden-like aspect of Golden grass, in contrast with specular reflectance calculated from the complex refractive index. A simple method is proposed to retrieve the complex dielectric function of fiber walls from the measured PAS and DRS intensities, using analytical equations obtained with hollow fiber topologies, in a low-energy region not easily accessible by photoelectron energy loss spectroscopy.

Fichier principal
Vignette du fichier
Golden Grass_diffuse scattering_2024.pdf (1.65 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)
Licence

Dates et versions

hal-04721544 , version 1 (14-10-2024)

Licence

Identifiants

Citer

Marcus Vinícius Santos da Silva, Denis G. F. David, Victor Mancir da Silva Santana, Christian Godet. Dielectric Function of Oriented Hollow Vegetal Fibers Retrieved from XPS, Diffuse Reflection, and Photoacoustic Spectroscopies. Brazilian Journal of Physics, 2024, ⟨10.1007/s13538-024-01628-2⟩. ⟨hal-04721544⟩
78 Consultations
102 Téléchargements

Altmetric

Partager

  • More