Theory of a non-traditional diffuse reflection-absorption technique intended for FTIR studies of conjugated polymers

Summary form only given. A new interpretation of the light reflection at dielectric-metal interface (DMI) in terms of the so called metal surface impedance (MSI) is proposed. It is shown that the reflection coefficient at DMI may be large enough for a dielectric with sufficiently large refractive index or (and) near the dielectric absorption band. Besides, this coefficient changes slowly in the vicinity of the dielectric absorption band. A new DRA technique based on these properties of the reflection coefficient permits a good interpretation in terms of MSI. High quality DRA spectra of common substances, which are directly comparable with the transmission spectra, are naturally explained and a comparison with other techniques is proposed. This technique is very useful for PDA owing to the possibility to obtain IR absorption spectra of the PDA´s in their actually pristine structure, on the one hand, and without the necessity to apply tedious and sometimes ambiguous Kramers-Kronig transformation, from the other.