Synchrotron-Based Spectroscopic Techniques: Mössbauer and High-Resolution Inelastic Scattering

Abstract

We summarize recent developments in selected synchrotron-based spectroscopy methods like nuclear resonant forward scattering (“synchrotron Mössbauer spectroscopy”), nuclear resonant inelastic x-ray scattering (“NRIXS”), and momentum-resolved inelastic x-ray scattering (“IXS”). The inelastic methods provide specific vibrational information, e.g., the phonon density of states, and in combination with diffraction data permits the determination of sound velocities under high pressure and high temperature. The Mössbauer method gives hyperfine interactions between the resonant nucleus and electronic environment like isomer shifts, quadrupole splittings, and magnetic fields, which provide important information on valence, spin state, and magnetic ordering. Both nuclear resonant methods use a nuclear resonant isotope as a probe and can be applied under high pressure and high temperature. The physical mechanism of the scattering processes will be discussed and several high-pressure high-temperature examples will be given.