Jean-Pascal Rueff

Pressure-Induced High-Spin to Low-Spin Transition in FeS Evidenced by X-Ray Emission Spectroscopy

We report the observation of the pressure-induced high-spin to low-spin transition in FeS using new high-pressure synchrotron x-ray emission spectroscopy techniques. The transition is evidenced by the disappearance of the low-energy satellite in the Fe Kb emission spectrum of FeS. Moreover, the phase transition is reversible and closely related to the structural phase transition from a manganese phosphidelike phase to a monoclinic phase. The study opens new opportunities for investigating the electronic properties of materials under pressure. [S0031-9007(99)08946-2]

Inelastic x-ray scattering by electronic excitations under high pressure

Investigating electronic structure and excitations under extreme conditions gives access to a rich variety of phenomena. High pressure typically induces behavior such as magnetic collapse and the insulator-metal transition in 3d transition metals compounds, valence fluctuations or Kondo-like characteristics in

Temperature- and pressure-induced spin-state transitions in LaCoO 3

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The GALAXIES beamline at the SOLEIL synchrotron: inelastic X-ray scattering and photoelectron spectroscopy in the hard X-ray range.

-electron systems, and coordination and bonding changes in molecular solids and glasses. This article reviews research concerning electronic excitations in materials under extreme conditions using inelastic x-ray scattering (IXS). IXS is a spectroscopic probe of choice for this study because of its chemical and orbital selectivity and the richness of information it provides. Being an all-photon technique, IXS has a penetration depth compatible with high pressure requirements. Electronic transitions under pressure in 3d transition metals compounds and

Electronic properties of transition-metal oxides under high pressure revealed by x-ray emission spectroscopy

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Atomic Auger Doppler effects upon emission of fast photoelectrons

-electron systems, most of them strongly correlated, are reviewed. Implications for geophysics are mentioned. Since the incident X-ray energy can easily be tuned to absorption edges, resonant IXS, often employed, is discussed at length. Finally studies involving local structure changes and electronic transitions under pressure in materials containing light elements are briefly reviewed.

Core-hole-clock spectroscopies in the tender x-ray domain

We report the continuous variation of the spin moment of cobalt in

Unified understanding of the valence transition in the rare-earth monochalcogenides under pressure

{\mathrm{LaCoO}}_{3}

Valence instability of YbCu2Si2through its magnetic quantum critical point

across its temperature and pressure-induced spin transitions evidenced with

CeRu4Sn6: a strongly correlated material with nontrivial topology.

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