A5102849422- Advanced X-ray Imaging Techniques
- Magnetism in coordination complexes
- Lanthanide and Transition Metal Complexes
- Electron Spin Resonance Studies
- Crystallography and Radiation Phenomena
- Advanced Electron Microscopy Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- X-ray Spectroscopy and Fluorescence Analysis
- Porphyrin and Phthalocyanine Chemistry
- Atomic and Subatomic Physics Research
- Laser-Plasma Interactions and Diagnostics
- Material Dynamics and Properties
- Electronic and Structural Properties of Oxides
- Solid-state spectroscopy and crystallography
- X-ray Diffraction in Crystallography
- Metal-Catalyzed Oxygenation Mechanisms
- Enzyme Structure and Function
- Photochemistry and Electron Transfer Studies
- High-pressure geophysics and materials
- Advanced Chemical Physics Studies
- Photoreceptor and optogenetics research
- Corrosion Behavior and Inhibition
- Covalent Organic Framework Applications
- Fluorine in Organic Chemistry
- Innovative Microfluidic and Catalytic Techniques Innovation
Paul Scherrer Institute
2019-2025
European Synchrotron Radiation Facility
2023-2025
Institut de Physique de Rennes
2014-2022
Centre National de la Recherche Scientifique
2015-2022
Université de Rennes
2015-2022
AlbaNova
2021
Pohang University of Science and Technology
2021
Stockholm University
2021
Linac Coherent Light Source
2021
SLAC National Accelerator Laboratory
2021
Significance The importance of molecular understanding the structure, dynamics. and properties liquid water is recognized in many scientific disciplines. Here, we study experimentally structure thermodynamics bulk as it supercooled by evaporation down to ∼228 K. unique aspect this work use ultrafast calorimetry that enables us determine specific-heat capacity unprecedentedly low temperatures. observed maximum about 218 J/mol/K at 229 K consistent with liquid–liquid critical point model...
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...
<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...
[ F e ( t r p y ) 2 ] + (terpy = 2,2′:6′,2″-terpyridine) is a transition metal complex where the spin state photoswitchable and properties of metal-centered quintet excited (5MC) can be tuned by substituting different electron withdrawing or donating groups on 4′ position terpyridine. To better understand physics determining photoswitching performance, deeper insight into positions relevant potential energy surfaces molecular structure 5MC needed. We present structural investigation based...
X-ray absorption spectroscopy (XAS) of 3d transition metals provides important electronic structure information for many fields. However, X-ray-induced radiation damage under physiological temperature has prevented using this method to study dilute aqueous systems, such as metalloenzymes, the catalytic reaction proceeds. Here we present a new approach enable operando XAS biological samples and demonstrate its feasibility with K-edge spectra from Mn cluster in photosystem II Fe-S centers I....
Photoswitchable 11 nm nanocrystals with the coordination network Cs{Co[Fe(CN)6]} were obtained using a template-free method. The recovered from colloidal solutions as solid materials surrounded by cetyltrimethylammonium (CTA) cations or embedded in organic polymer polyvinylpyrrolidone (PVP). Complementary magnetic, spectroscopic, and structural techniques, including EPR spectroscopy, reveal majority (∼70%) of low-spin photoactive diamagnetic CoIIIFeII pairs located core mixture CoIIFeII...
The extension of transient grating spectroscopy to the x-ray regime will create numerous opportunities, ranging from study thermal transport in ballistic charge, spin, and energy transfer processes with atomic spatial femtosecond temporal resolution. Studies involving complicated split-and-delay lines have not yet been successful achieving this goal. Here we propose a novel, simple method based on Talbot effect for converging beams, which can easily be implemented at current free electron...
The Bernina instrument at the SwissFEL Aramis hard X-ray free-electron laser is designed for studying ultrafast phenomena in condensed matter and material science. Ultrashort pulses from an optical system covering a large wavelength range can be used to generate specific non-equilibrium states, whose subsequent temporal evolution probed by selective scattering techniques 2–12 keV. For that purpose, beamline equipped with elements which tailor beam size energy, as well pulse-to-pulse...
Abstract Photosystem I (PS I) has a symmetric structure with two highly similar branches of pigments at the center that are involved in electron transfer, but shows very different efficiency along branches. We have determined cyanobacterial PS room temperature (RT) using femtosecond X-ray pulses from an free laser (XFEL) clear expansion entire protein complex direction membrane plane, when compared to previous cryogenic structures. This trend was observed by complementary datasets taken...
In this paper we study the out-of-equilibrium dynamics associated with photoinduced charge-transfer (CT) in cyanide-bridged Co-Fe Prussian blue analogue nanocrystals. these coordination networks, structural trapping of CT polaron involves local electronic and reorganizations. Femtosecond X-ray optical absorption spectroscopies show that process occurs on similar timescale for particles 11 nm 70 sizes. The spin transition, elongating Co-N bonds driving CoIIIFeII → CoIIFeIII CT, activates...
The structural changes of water upon deep supercooling were studied through wide-angle x-ray scattering at SwissFEL. experimental setup had a momentum transfer range 4.5 Å-1, which covered the principal doublet structure factor water. oxygen-oxygen was obtained for temperatures down to 228.5 ± 0.6 K. Similar previous studies, second diffraction peak increased strongly in amplitude as change accelerated toward local tetrahedral supercooling. We also observed an anomalous trend position (q2)....
The resonant excitation of electronic transitions with coherent laser sources creates quantum superpositions the involved states. Most time-resolved studies have focused on gases or isolated subsystems embedded in insulating solids, aiming for applications information. Here, we focus control orbital wavefunctions correlated material Tb2Ti2O7, which forms an interacting spin liquid ground state. We show that a strong THz pulse superposition lowest energy Tb 4f coherence manifests itself as...
The [Fe(L222 N5 )(CN)2 ] compound, where L222 refers to the macrocyclic Schiff-base ligand, 2,13-dimethyl-3,6,9,-12,18-pentaazabicyclo[12.3.1]octadeca-1(18),2,12,14,- 16-pentaene, is a photomagnetic FeII based coordination which undergoes light-induced excited spin-state trapping (LIESST). low spin state hexacoordinated and high heptacoordinated. This system also serves as complex for design of trinuclear or one-dimensional compounds made other types bricks with diverse coordinated metals....
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.
Abstract The layered transition-metal dichalcogenide WTe 2 is characterized by distinctive transport and topological properties. These properties are largely determined electronic states close to the Fermi level, specifically electron hole pockets in sea. In principle, these can be manipulated changes crystal structure. precise impact of particular structural on a strong function specific nature atomic displacements. Here, we report time-resolved X-ray diffraction infrared reflectivity...
[Ce(III)Cl6]3–, with its earth-abundant metal element, is a promising photocatalyst facilitating carbon–halogen bond activation. Still, the structure of reaction intermediate has yet to be explored. Here, we applied time-resolved X-ray liquidography (TRXL), which allows for direct observation structural details intermediates, investigate photocatalytic [Ce(III)Cl6]3–. Structural analysis TRXL data revealed that excited state [Ce(III)Cl6]3– Ce–Cl bonds are shorter than those ground and...
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...
Ultrafast electron delocalization induced by a femtosecond laser pulse is well-known process in which electrons are ejected from the ions within duration. However, very little known about speed of localization out an gas correlated metals, i.e., capture ion. Here, we demonstrate means pump-probe x-ray techniques across Eu L3 absorption edge that EuNi2(Si0.21Ge0.79)2 intermetallic material occurs few hundred femtoseconds after optical excitation. Spectroscopy and diffraction data collected...
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...
[Fe(terpy)2]2+ (terpy = 2,2':6',2''-terpyridine) is a transition metal complex where the spin state photoswitchable and properties of metal-centered quintet excited (5MC) can be tuned by substituting different Electron Withdrawing (EW) or Donating (ED) groups on 4' position terpyridine. To better understand physics determining photoswitching performance, deeper insight into positions relevant potential energy surfaces molecular structure 5MC needed. We present structural investigation based...
Speckle patterns manifesting from the interaction of coherent X-rays with matter offer a glimpse into dynamics nanoscale domains that underpin many emergent phenomena in quantum materials. While average structure can be followed time-resolved X-ray diffraction, ultrafast evolution local structures nonequilibrium conditions have thus far eluded detection due to experimental limitations, such as insufficient flux. Here we demonstrate speckle visibility experiment using split-and-delay setup at...
Nonlinear wave mixing in the X-ray range can provide valuable insights into structural and electron dynamics of atomic molecular systems on ultrafast time scales, with state- site-selectivity resolution. This promising experimental toolbox was so far limited by requiring at least one near-visible laser, thus preventing core-shell two-dimensional spectroscopy. In this work, we demonstrate generation background-free all-X-ray four-wave (XFWM) signals from a dilute gaseous sample (Ne). The...