A5010426171- Material Dynamics and Properties
- Glass properties and applications
- nanoparticles nucleation surface interactions
- High-pressure geophysics and materials
- Magnetism in coordination complexes
- Ion-surface interactions and analysis
- Quantum, superfluid, helium dynamics
- Relativity and Gravitational Theory
- Cosmology and Gravitation Theories
- Advanced Thermodynamics and Statistical Mechanics
- Black Holes and Theoretical Physics
- Porphyrin and Phthalocyanine Chemistry
- Experimental and Theoretical Physics Studies
- Liquid Crystal Research Advancements
- Educational Methods and Media Use
- Plant Water Relations and Carbon Dynamics
- Computational Physics and Python Applications
- Electron Spin Resonance Studies
- Synthesis and Properties of Aromatic Compounds
- Tree-ring climate responses
- Molecular spectroscopy and chirality
- Inorganic Fluorides and Related Compounds
- Metal-Catalyzed Oxygenation Mechanisms
- Educational Games and Gamification
- Fluid Dynamics and Heat Transfer
Max Planck Institute for Polymer Research
2024-2025
Johannes Gutenberg University Mainz
2022-2025
European X-Ray Free-Electron Laser
2025
Czech Academy of Sciences, Institute of Physics
2025
Stockholm University
2020-2024
AlbaNova
2020-2024
We prepared bulk samples of supercooled liquid water under pressure by isochoric heating high-density amorphous ice to temperatures 205 ± 10 kelvin, using an infrared femtosecond laser. Because the sample density is preserved during ultrafast heating, we could estimate initial internal 2.5 3.5 kilobar in phase. After expanded rapidly, and captured resulting decompression process with x-ray laser pulses at different pump-probe delay times. A discontinuous structural change occurred which...
Recent experiments continue to find evidence for a liquid-liquid phase transition (LLPT) in supercooled water, which would unify our understanding of the anomalous properties liquid water and amorphous ice. These are challenging because proposed LLPT occurs under extreme metastable conditions where freezes crystal on very short time scale. Here, we analyze models show that coexistence distinct high-density low-density phases may be observed by subjecting (LDA) ice ultrafast heating. We then...
Abstract A comprehensive insight into ultrafast dynamics of photo-switchable materials is desired for efficient control material properties through light excitation. Here, we study a polycrystalline spin crossover thin film as prototypical example and reveal the sequential photo-switching dynamics, from local molecular rearrangement to global lattice deformation. On earliest femtosecond timescale, structural occurs within constant unit-cell volume two-step process, involving initial...
<title>Abstract</title> The process of merging bubbles or droplets with one another a continuous phase is known as coalescence.<sup>1</sup> It takes place from the microscale, e.g., in technological applications such contrast-enhanced ultrasound medicine, to macroscale, planet and star formation. Coalescence water an important nature, Earth’s troposphere for growth raindrops<sup>2</sup>. Usually coalescence studied at ambient temperature, but even clouds it temperature range down 235 K,...
Although the unique structure of helicenes resembles molecular springs, effects their extension-contraction cycles on properties have rarely been explored. Here, we investigated fluorescence two π-extended [n]helicenes with different helical lengths n, named [7] and [9], under high pressures in a diamond anvil cell. The experimental results showed that compound longer length, exhibited more sensitive response than both crystalline solvated states upon compression. Theoretical calculations...
Although the unique structure of helicenes resembles molecular springs, effects their extension–contraction cycles on properties have rarely been explored. Here, we investigated fluorescence two π‐extended [n]helicenes with different helical lengths n, named [7] and [9], under high pressures in a diamond anvil cell. The experimental results showed that compound longer length, exhibited more sensitive response than both crystalline solvated states upon compression. Theoretical calculations...
<title>Abstract</title> In spite of four decades research on vitrified glassy water droplets, their flow properties in the deeply supercooled regime below 160 K have remained elusive. However, they are key to astrophysical processes where molecules transported between interfaces or state. Here we observe coalescence a deposit consisting thousands micrometer-sized droplets ~123 and ~140 K. Both electron microscopy small-angle X-ray scattering indicate disappearance droplet at time scale...
Using time-resolved wide-angle X-ray scattering, we investigated the early stages (10 μs–1 ms) of crystallization supercooled water, obtained by ultrafast heating high- and low-density amorphous ice (HDA LDA) up to a temperature T = 205 K ± 10 K. We have determined that crystallizing phase is stacking disordered (Isd), with maximum cubicity χ 0.6, in agreement predictions from molecular dynamics simulations at similar temperatures. However, note growing small portion hexagonal (Ih) was also...
High-density (HDA) and low-density amorphous ices (LDA) are believed to be counterparts of the high- liquid phases water, respectively. In order better understand how vibrational modes change during transition between two solid states, we present infrared spectroscopy measurements, following decoupled OD-stretch (
The phase transition between water and ice is ubiquitous one of the most important phenomena in nature. Here, we performed time-resolved x-ray scattering experiments capturing melting recrystallization dynamics ice. ultrafast heating I induced by an IR laser pulse probed with intense pulse, which provided us direct structural information on different length scales. From wide-angle (WAXS) patterns, molten fraction, as well corresponding temperature at each delay, were determined. small-angle...
Amorphous ice is commonly used as a noncrystalline matrix for protecting sensitive biological samples in cryogenic electron microscopy (cryo-EM). The amorphization process of water complex, and at least two amorphous states different densities are known to exist, high- low-density ices (HDA LDA). These forms considered be the counterparts distinct liquid states, namely, water. Herein, we investigate HDA LDA transition using diffraction cryo-EM. observed phase induced by impact electrons,...
Here, we investigate the hypothesis that despite existence of at least two high-density amorphous ices, only one liquid state exists in water. We prepared a very-high-density ice (VHDA) sample and rapidly increased its temperature to around 205 ± 10 K using laser-induced isochoric heating. This falls within so-called “no-man’s land” well above glass-liquid transition, wherein IR laser pulse creates metastable state. Subsequently, this (HDL) water decompresses over time, examined...
<title>Abstract</title> Knowing the pressure dependence of glass forming liquids is important in various contexts. Here, we study case supercooled water, which has at least two different amorphous states with densities. The dependencies transitions are predicted to show opposite behaviour, crossing P-T plane elevated pressure. While experimental identification transition and cold temperatures technically difficult, measurements on bulk water ices even more challenging, as interrupted by...
<title>Abstract</title> Various metastable ice phases and their complicated transition pathways have been found by pressurization at low temperatures, where slow kinetics high metastability can be easily achieved. In contrast, such diversity is less expected room or elevated temperatures. Here, using a dynamic diamond anvil cell X-ray free electron laser techniques, we demonstrate that supercompressed water transforms into VI through multiple freezing–melting temperature, hidden within the...
The phase transition between water and ice is ubiquitous one of the most important phenomena in nature. Here, we performed time-resolved x-ray scattering experiments capturing melting recrystallization dynamics ice. ultrafast heating I induced by an IR laser pulse probed with intense pulse, which provided us direct structural information on different length scales. From wide-angle (WAXS) patterns, molten fraction, as well corresponding temperature at each delay, were determined. small-angle...
Abstract In Newtonian gravity it is a moot question whether energy should be localized in the field or inside matter. An argument from relativity suggests compromise which contribution vacuum positive definite. We show that same implied by Noether’s theorem applied to variational principle for perfect fluids, if we assume Dirichlet boundary conditions on potential. then analyse thought experiment due Bondi and McCrea gives clean example of inductive transfer gravity. Some history problem included.
In Newtonian gravity it is a moot question whether energy should be localized in the field or inside matter. An argument from relativity suggests compromise which contribution vacuum positive definite. We show that same implied by Noether's theorem applied to variational principle for perfect fluids, if we assume Dirichlet boundary conditions on potential. then analyse thought experiment due Bondi and McCrea gives clean example of inductive transfer gravity. Some history problem included