A5028402904- High-pressure geophysics and materials
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Metallurgical Processes and Thermodynamics
- Nuclear Materials and Properties
- Geological and Geochemical Analysis
- Rare-earth and actinide compounds
- Hydrogen Storage and Materials
- Diamond and Carbon-based Materials Research
- NMR spectroscopy and applications
- Nuclear Physics and Applications
- Heat transfer and supercritical fluids
- Subcritical and Supercritical Water Processes
- earthquake and tectonic studies
- Advanced Chemical Physics Studies
- Thermochemical Biomass Conversion Processes
- Iron and Steelmaking Processes
- Geochemistry and Geologic Mapping
- Geological Studies and Exploration
- Inorganic Chemistry and Materials
- Combustion and flame dynamics
- Advanced NMR Techniques and Applications
- Perovskite Materials and Applications
Shanghai Advanced Research Institute
2024-2025
Center for High Pressure Science and Technology Advanced Research
2021-2024
University of Bayreuth
2017-2022
Center for High Pressure Science & Technology Advanced Research
2022
Bern University of Applied Sciences
2020
ETH Zurich
2014-2018
RWTH Aachen University
2015-2018
Leipzig University
2011-2015
École Polytechnique Fédérale de Lausanne
2014
Forschungsinstitut für Edelmetalle und Metallchemie
1968
In recent years, metal hydride research has become one of the driving forces high-pressure community, as it is believed to hold key superconductivity close ambient temperature. While numerous novel compounds have been reported and extensively investigated for their superconducting properties, little attention focused on atomic electronic states hydrogen, main ingredient in these compounds. Here, we present combined 1H- 139La-NMR data lanthanum superhydrides, LaHx, (x = 10.2 − 11.1),...
The lanthanum-hydrogen system has attracted significant attention following the report of superconductivity in LaH10 at near-ambient temperatures and high pressures. Phases other than are suspected to be synthesized based on both powder X-ray diffraction resistivity data, although they have not yet been identified. Here, we present results our single-crystal studies this system, supported by density functional theory calculations, which reveal an unexpected chemical structural diversity...
Hydrogen bond symmetrisations in H-bonded systems triggered by pressure-induced nuclear quantum effects (NQEs) is a long-known concept but experimental evidence high-pressure ices has remained elusive with conventional methods. Theoretical works predicted quantum-mechanical tunneling of protons within water to occur at pressures above 30 GPa, and the H-bond symmetrisation transition 60 GPa. Here we used 1H-NMR on ice up 97 demonstrate that NQEs govern behavior hydrogen bonded VII already...
The experimental study of hydrogen-bonds and their symmetrization under extreme conditions is predominantly driven by diffraction methods, despite challenges localising or probing the hydrogen subsystems directly. Until recently, H-bond has been addressed in terms either nuclear quantum effects, spin crossovers direct structural transitions; often leading to contradictory interpretations when combined. Here, we present high-resolution in-situ 1H-NMR experiments diamond anvil cells...
Water in Earth’s deep interior is predicted to be hydroxyl (OH − ) stored nominally anhydrous minerals, profoundly modulating both structure and dynamics of Earth's mantle. Here, we use a high-dimensional neuro-network potential machine learning algorithm investigate the weight percent water incorporation stishovite, main constituent subducted oceanic crust. We found that stishovite prefer forming medium- long-range ordered superstructures, featuring one-dimensional (1D) channels....
A new pathway to nuclear magnetic resonance (NMR) spectroscopy for picoliter-sized samples (including those kept in harsh and extreme environments, particularly diamond anvil cells) is introduced, using inductively coupled broadband passive electromagnetic lenses, locally amplify the field at isolated sample, leading an increase sensitivity. The lenses are adopted geometrical restrictions imposed by a toroidal indenter cell yield signal-to-noise ratios pressures as high 72 GPa initial sample...
An approach for inline monitoring of organic syntheses in a microfluidic droplet chip <italic>via</italic> surface-enhanced Raman spectroscopy is presented. In proof concept it was successfully applied to follow thiazole real-time.
Chip-integrated electrically connected stationary SERS targets enable interference-free consecutive surface-enhanced Raman measurements by assisted substrate regeneration.
Charged molecular species, such as ${{[{\mathrm{N}}_{2}]}^{x}}^{\text{--}}$, ${{[{\mathrm{O}}_{2}]}^{x}}^{\text{--}}$, ${{[{\mathrm{C}}_{2}]}^{x}}^{\text{--}}$, and ${{[{\mathrm{S}}_{2}]}^{x}}^{\text{--}}$, follow the paradigm of carrying integer values electrons. Here, ${\mathrm{Na}}_{3}{({\mathrm{N}}_{2})}_{4}$, ${\mathrm{Ca}}_{3}{({\mathrm{N}}_{2})}_{4}$, ${\mathrm{Sr}}_{3}{({\mathrm{N}}_{2})}_{4}$, $\mathrm{Ba}{({\mathrm{N}}_{2})}_{3}$ compounds were produced characterized 70 GPa...
Following the recent report by Dasenbrock-Gammon et al. [Nature 615, 244–250 (2023)] of near-ambient superconductivity in nitrogen-doped lutetium trihydride (LuH3−δNε), significant debate has emerged surrounding composition and interpretation observed sharp resistance drop. Here, we meticulously revisit these claims through comprehensive characterization investigations. We definitively identify reported material as dihydride (LuH2), resolving ambiguity its composition. Under similar...
In this work, we examine thermal spallation drilling through finite element modeling of the uncoupled quasi-static thermoelastic problem describing stresses induced by rapid and localized heating a uniaxially pre-stressed rock core. The numerical procedure is verified using method manufactured solutions, optimal order accuracy demonstrated. From series experiments, present temperature stress profiles along centerline core which are discussed qualitatively with respect to corresponding...
Nuclear magnetic resonance experiments reveal how the electronic properties of hydrogen in iron hydride change under extreme pressure, a step toward understanding onset high-temperature superconductivity metal hydrides.
Increasing demands on the electric arc furnace (EAF) with regard to sustainability and energy efficiency are leading various technological innovations. To reduce carbon footprint of steel production in EAFs, fossil coal can be substituted by biochar as investigated within GreenEAF research projects. Palm kernel shells (PKS) used for industrial long‐term trials showed no negative impact product quality or consumption technically feasible, but led different reaction behavior. For further...
The atomic and electronic structures of ${\mathrm{Cu}}_{2}\mathrm{H}$ CuH have been investigated by high-pressure nuclear magnetic resonance spectroscopy up to 96 GPa, X-ray diffraction 160 density functional theory-based calculations. Metallic was synthesized at a pressure 40 semimetallic 90 found stable GPa. For ${\mathrm{Cu}}_{2}\mathrm{H}$, experiments computations show an anomalous increase in the state Fermi level for hydrogen $1s$ states formation network range 43--58 together with...
A new design of a non-magnetic high-pressure anvil cell for nuclear magnetic resonance (NMR) experiments at Giga-Pascal pressures is presented, which uses micro-coil inside the pressurized region high-sensitivity NMR. The comparably small has length 22 mm and diameter 18 mm, so it can be used with most NMR magnets. performance demonstrated external-force vs. internal-pressure experiments, shown to perform well up 23.5 GPa using 800 μm 6H-SiC large cone Boehler-type anvils. (1)H, (23)Na,...
The high amount of latent and sensible enthalpy discharged from the melting process in an electric arc furnace (EAF) through off-gas offers potential for waste heat recovery. Evaporative cooling systems (ECSs) installed at dedusting some EAFs are utilising this steam generation subsequent usage further applications. Within following paper, optimisation approaches recovery examined comparatively by means exergetic analysis. Thereby, focus is on excessive intake false air into system to ensure...
Using a density-functional-theory-based approach, we explore the symmetrization and proton dynamics in ice-VII, for which recent high-pressure NMR experiments indicate significant pressure-range of $20-95$ GPa. We directly sample potential seen by find continuous transition from double- to single-well character over pressure range 2 130 GPa accompanied agreement with experiments.
Ce3+-doped SrS phosphors with a charge-compensating Na+ addition were successfully synthesized via solid-state reaction method, and the related X-ray diffraction patterns can be indexed to rock-salt-like crystal structure of Fm3̅m space group. SrS:(Ce3+)x (0.005 ≤ x 0.05) SrS:(Ce3+)0.01,(Na+)y y 0.030) excited by 430 nm UV-Vis light, targeted 5d1 → 4f1 transition Ce3+. The composition-optimized SrS:(Ce3+)0.01, (Na+)0.015 showed an intense broad emission band at λ = 430-700 nm. doping was...
$\delta$-AlOOH is of significant crystallochemical interest due to a subtle structural transition near 10 GPa from $P2_1nm$ $Pnnm$ structure, the nature and origin hydrogen disorder, symmetrization O-H$\cdots$O bond their interplay. We perform series density functional theory based simulations in combination with high-pressure nuclear magnetic resonance experiments on up 40 goal better characterize potential therefore disorder. Simulations predict phase agreement our at $10-11$ $14.7$ GPa....
Recent developments in situ nuclear magnetic resonance (NMR) spectroscopy under extreme conditions have led to the observation of a wide variety physical phenomena that are not accessible with standard high-pressure experimental probes. However, inherent di- or quadrupolar line broadening diamond anvil cell (DAC)-based NMR experiments often limits detailed investigation local atomic structures, especially if different phases environments coexist. Here, we describe our progress development...