Total-reflection inelastic X-ray scattering

Many readers of this news column are familiar with total-reflection X-ray fluorescence (TXRF). They also know that experiments can be done with a wavelength-dispersive mode, besides ordinary measurement with a silicon drift detector or a Si(Li) detector. If the spectrometer is optimized to see inelastic X-ray scattering spectra, what happens? Very recently, a research team led by Dr. P. H. Fuoss (Argonne National Laboratory, USA) published a very interesting report. The experiment used soft X-rays to observe the electronic structure of a 10-nm-thick La_0.6Sr_0.4CoO₃ epitaxial layer grown on a SrTiO₃ substrate. By comparing data acquired under total X-ray reflection and penetrating conditions, it was found that the O K-edge spectra from a 10 nm thin film and that from the underlying substrate can be separated successfully. For more information, see the papers, "Total-Reflection Inelastic X-Ray Scattering from a 10-nm Thick La0.6Sr0.4CoO3 Thin Film", T. T. Fister et al., Phys. Rev. Lett. 106, 037401 (2011).