Ultrahigh Vacuum Fourier Transform Infrared Spectroscopy (UHV-FTIRS)
We have designed a new ultrahigh vacuum (UHV) apparatus which combines a state-of-the-art vacuum IR spectrometer (Bruker, VERTEX 80v) with a novel UHV system (Prevac) consisting of load-lock, distribution, measurement and high-pressure chambers. The innovative design allows carrying out both reflection-absorption infrared spectroscopy (RAIRS) experiments at grazing incidence on well-defined single crystal surfaces and FTIR transmission measurements for powder particles in a wide pressure range from UHV to ambient conditions. A further unique feature of the apparatus is the entirely evacuated optical path to avoid atmospheric moisture adsorption, thus resulting in a superior sensitivity and stability of the system, an essential prerequisite for monitoring molecular species adsorbed on oxide single-crystal surfaces. The unique performance of this new apparatus with regard to the spectroscopic characterization of adsorbates on oxide single crystals as well as on powder particles has been demonstrated by case studies for two different materials, TiO2 and ZnO.
Fig.: UHV-FTIR apparatus