X-Ray Absorption with Transmission X-Ray Microscopes

Abstract

In this section we focus on the use of transmission X-ray microscopy (TXM) to measure the XAS spectra. In the last decade a range of soft X-ray and hard X-ray TXM microscopes have been developed, allowing the measurement of XAS spectra with 10–100 nm resolution. In the hard X-ray range the TXM experiments pose the same restrictions on in situ experiments as bulk XAS experiments, allowing experiments with capillaries to study catalysts under working conditions. In the soft X-ray range, dedicated transmission nanoreactors are needed. Considering catalysts the main result the in situ TXM experiments are the determination of nanometer range variations of catalysts under working conditions. An important property of X-rays is their short wavelength below 1 nm. This allows direct imaging of catalysts in scanning mode or full field mode. In contrast, visible light with an energy of 1 eV has a diffraction limited resolution of approximately 500 nm and VUV light with an energy of 10 eV has a diffraction limit of ~50 nm.