Methods#
Investigation techniques#
Spectroscopy#
Spectroscopy is the scientific study and analysis of the interaction between matter and electromagnetic radiation. It involves the measurement and interpretation of spectra showing characteristic patterns of wavelengths (frequencies or wavenumbers) of electromagnetic radiation emitted, absorbed, or scattered by a substance. The electromagnetic radiation used in spectroscopy can cover a wide range of wavelengths, including radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. Different techniques and instruments are employed to study specific regions of the electromagnetic spectrum, each providing unique information about the sample under investigation. This thesis focusses on the absorption of IR radiation.
Classical physics uses Maxwell equations to describe electromagnetic radiation as oscillating electric (E) and magnetic (B) orthogonal fields which, in vacuum, propagate as a harmonic wave at the speed of light (c). The wavelength (λ) and frequency (ν) used to characterise the different regions of the electromagnetic spectrum are related via the following equation:
where c = 3 x 108 m.s-1
Quantum physics however describe
Note
Insérer ici le diagramme infrared quand je l’aurais retrouvé …