A5020989101- Quasicrystal Structures and Properties
- X-ray Diffraction in Crystallography
- Magnetism in coordination complexes
- Organic and Molecular Conductors Research
- Solid-state spectroscopy and crystallography
- Crystallography and molecular interactions
- Crystallization and Solubility Studies
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Synthesis and Properties of Aromatic Compounds
- Superconducting Materials and Applications
- Material Science and Thermodynamics
- Electron Spin Resonance Studies
- Liquid Crystal Research Advancements
- Catalysis and Oxidation Reactions
- Photonic Crystals and Applications
- Supramolecular Self-Assembly in Materials
- Intermetallics and Advanced Alloy Properties
- Cellular and Composite Structures
- High-pressure geophysics and materials
- Microstructure and mechanical properties
- Electron and X-Ray Spectroscopy Techniques
- Chemical Thermodynamics and Molecular Structure
- Advanced Physical and Chemical Molecular Interactions
- Geophysics and Sensor Technology
European Synchrotron Radiation Facility
2022-2025
Institut de Physique de Rennes
2014-2024
Université de Rennes
2013-2024
Centre National de la Recherche Scientifique
2013-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2013-2019
Marietta College
2019
CEA Grenoble
2013-2019
Université Grenoble Alpes
2013-2019
Institut Nanosciences et Cryogénie
2013-2019
Laboratoire de physique des Solides
2014-2015
Abstract Ultrafast photoinduced phase transitions at room temperature, driven by a single laser shot and persisting long after stimuli, represent emerging routes for ultrafast control over materials’ properties. Time-resolved studies provide fundamental mechanistic insight into far-from-equilibrium electronic structural dynamics. Here we study the transformation of Rb 0.94 Mn Co 0.06 [Fe(CN) 6 ] 0.98 material, designed to exhibit 75 K wide thermal hysteresis around temperature between III Fe...
Abstract One of the main challenges in ultrafast material science is to trigger phase transitions with short pulses light. Here we show how strain waves, launched by electronic and structural precursor phenomena, determine a coherent macroscopic transformation pathway for semiconducting-to-metal transition bistable Ti 3 O 5 nanocrystals. Employing femtosecond powder X-ray diffraction, measure lattice deformation as function time. We monitor early intra-cell distortion around light absorbing...
This study explores laser‐induced crystallization and amorphization processes in thin films of Ge‐rich GST (GGST), a tailored phase change material (PCM), monitored situ using synchrotron X‐ray diffraction. GGST's high temperature makes it promising for embedded memory applications. Experiments employed an 800 nm femtosecond laser source, varying fluence pulse parameters to induce transitions. Key findings include fluence‐dependent thresholds crystallizing Ge GST, along with precise control...
<title>Abstract</title> Recently developed ceramic material Ti<sub>3</sub>O<sub>5</sub> exhibits fascinating application properties, from ultrafast switching between metallic and insulating phases to light-to-heat conversion storage. While the states conferring such properties are not spatially homogeneous, origin of phase separation link coexistence dynamics, key for stability states, is still little known. In this work, we use time-resolved X-ray diffraction numerical simulations establish...
Abstract Spin‐crossover (SCO) complexes have drawn significant attention for the possibility to photoswitch their electronic spin state on a sub‐picosecond timescale at molecular level. However, multi‐step mechanism of laser‐pulse‐induced switching in solid is not yet fully understood. Here, time‐resolved synchrotron X‐ray diffraction used follow dynamics crystal lattice response picosecond laser excitation nanometric thin films SCO complex [Fe(HB(1,2,4‐triazol‐1‐yl) 3 ) 2 ]. The observed...
Abstract Time-resolved studies with temporal resolution that separate molecular level dynamics from macroscopic changes, allow clear distinction between the time scales of different degrees freedom involved. Cooperative switching in solid state is exemplified by spin crossover phenomenon crystals transition metal complexes. Here we show existence a delay crystalline volume increase, and cooperative state. Using 100 ps X-ray diffraction, track structure lattice during photoinduced low to high...
Abstract n -Dodecane/urea is a member of the prototype series -alkane/urea inclusion compounds. At room temperature, it presents quasi-one dimensional liquid-like state for confined guest molecules within rigid, hexagonal framework urea host. lower temperatures, we report existence two other phases. Below T c =248 K there appears phase with rank four superspace group P6 1 22(00 γ ), one typically observed at temperature in compounds longer molecules. A misfit parameter, defined by ratio γ= h...
We have studied by X‐ray diffraction the phase transition of microcrystals rubidium manganese hexacyanoferrate, for which combined electron transfer and structural reorganization are responsible a change magnetic properties. The Rb 0.94 Mn[Fe(CN) 6 ] 0.98 · 2.5H 2 O system undergoes between tetragonal Fe II (S = 0)–CN–Mn III 2) cubic 1/2)–CN–Mn 5/2) phases. thermal equilibrium shows broad regime bistability, appearance hysteresis in approximate 185–300 K temperature range. used deposited...
Photo-induced charge-transfer in the RbMnFe Prussian blue analogue is coupled to a Jahn–Teller distortion, which results an anisotropic crystalline lattice reorganization.
n-Heptane/urea is an aperiodic inclusion compound in which the ratio of host and guest repeats along channel axis very close to unity found have a constant value (0.981) from 280 K 90 K. Below K, two phase transitions are observed. The first (T(c1) = 145 K) ferroelastic transition that generates superstructure reflections for while leaving with 1D order. second (T(c2) 130 "phase ordering" four-dimensional structure (P2(1)11(0βγ)) pronounced host-guest intermodulation temperature dependent...
Upon cooling, the aperiodic inclusion compound $n$-nonadecane/urea presents a hexagonal-to-orthorhombic group-subgroup phase transition at ${T}_{\mathrm{cl}}$ that increases structure's superspace dimensionality from four to five. This paper reports on pretransitional phenomena in such high-dimensional space, generalizing critical results previously reported lower dimensionality. Very high-resolution diffraction data reveal anomalously large correlation lengths along direction, with all...
We present a newly developed laser-driven shock compression platform at the ID09 beamline of European Synchrotron Radiation Facility (ESRF). This combines custom high-power EKSPLA laser with ESRF's high-energy X-ray pulses to perform in situ, time-resolved diffraction (XRD) measurements materials under well characterized, moderate pressure (up 1 Mbar) and short-duration waves. Its purpose is serve as driver study dynamic pressure, focusing on phase transitions condensed matter. provide...
The MOF $[{\text{Fe(tvp)}}_{2}{(\text{NCS})}_{2}]\ifmmode\cdot\else\textperiodcentered\fi{}2\text{BzCHO}$ is demonstrated to undergo a complex sequence of phase transitions and spin-crossover behavior its constitutive ${\text{Fe}}^{\text{II}}$ ions upon adsorption benzaldehyde guest molecules. Our study, combining Raman synchrotron x-ray diffraction measurements on single crystal, reveals that the conversion from pure high-spin low-spin phases implies rich intermediate phases, with symmetry...
Aperiodic composite crystals present long-range order without translational symmetry. These materials may be described as the intersection in three dimensions of a crystal which is periodic higher-dimensional space. In such materials, symmetry breaking must structural changes within these crystallographic superspaces. The increase number superspace groups with dimension allows many more solutions. This illustrated n-nonadecane-urea, revealing fifth phase at low temperature.
This paper reports on symmetry breaking in the aperiodic inclusion compound $n\text{-octadecane/urea}$ and its isotopomer $n\text{-octadecane/urea-}{d}_{4}$. The high-symmetry phase is described by a hexagonal rank-4 superspace group. Pretransitional phenomena this crystallographic reveal competing short-range-ordering within phase. Very high-resolution diffraction data show that critical scattering appears at inequivalent points four-dimensional Brillouin zone, although first transition...
The paper describes measurement and analysis of beam instability made at SOLEIL in comparison with the expectation using numerically estimated impedance budget. A multibunch is found to be under a strong influence resistive-wall fast beam-ion instabilities, way that largely depends on local position bunch train. For single bunch, measured reactive turns out larger by nearly factor two than calculated all three planes. roughness due NEG coating assessed as possible cause.
The complex relaxation from the photoinduced high-spin phase (PIHS) to low-spin of bimetallic two-dimensional coordination spin-crossover polymer [Fe[(Hg(SCN) 3 ) 2 ](4,4′-bipy) ] n is reported. During thermal relaxation, commensurate and incommensurate spin-state concentration waves (SSCWs) form. However, contrary steps forming at equilibrium, associated with long-range SSCW order, SSCWs during PIHS correspond short-range revealed by diffuse X-ray scattering. This interpreted as resulting...
The intergrowth crystal of n-tetracosane/urea presents a misfit parameter, defined by the ratio γ = ch /cg (chost/cguest), that is very close to commensurate value (γ ≅ 1/3). High-resolution diffraction studies presented here reveal an aperiodic parameter 0.3369, which found be constant at all temperatures studied. A complex sequence structural phases reported. high temperature phase (phase I) exists in four-dimensional superspace group P6122(00γ). At Tc1 179(1) K, ferroelastic transition...
The paper describes the bunch by transverse feedback system developed and implemented at SOLEIL. In order to cope with diverse beam conditions involving multibunch single instabilities, a digital has been developed. While BPM, RF frontend stripline in house are used chain, SPring-8 solution was chosen for processor its proven performance elsewhere. commissioning of as well attained is presented.
Phase changes in individual submicron crystals of Ti3O5 are studied by situ transmission electron microscopy. An irreversible transition from the stable beta- to metastable lambda phase is induced slow temperature thermal equilibrium or nanosecond laser pulses. The expansion during transformation measured real space imaging and reciprocal diffraction. incomplete suppressed under heating indicates that kinetic barrier for transformations beta high-temperature alpha higher than bulk material....
Abstract The Rb 0.94 Mn Co 0.06 [Fe(CN) 6 ] 0.98 material was designed to exhibit a 75 K wide thermal hysteresis around room temperature, associated with bistability between the low temperature III Fe II tetragonal phase and high cubic phase. We have recently shown that single laser pulse can be used drive, at photoinduced transition from By using specific powder sample streaming technique, we could monitor by time‐resolved X‐ray diffraction how ultrafast out‐of‐equilibrium dynamics, imposed...