Stroboscopic x-ray pulses scatter from a vibrating crystal and reveal how energy moves
Atoms and the electrons that hold them together store energy in their electronic bonding structure and in their atomic vibrations. X-ray laser scattering techniques, which can record electron and atom motion at ultra-fast time scales, have been used to measure and track the transfer of energy from one atomic-scale storage mode to another.
Image courtesy of SLAC National Accelerator Laborator
A series of x-ray scattering images are taken at ultrafast time intervals (Δt) with an x-ray laser after excitation with an infra-red source that energizes the vibrational modes of a germanium crystal. The time domain images yield a vibrational intensity map (w) relative to the orientation and spacing (q) of the atomic crystalline array.
This x-ray scattering technique allows scientists to track the motion of atoms as they respond to sudden changes in their energy state. Tracking the mode of energy flow is critical to understanding the fundamental dynamics of energy conversion materials.
X-ray scattering can measure and describe the atomic positions in technologically important crystalline solids such as silicon and germanium. After an excitation by heat or radiation, the flow of energy can be tracked as it moves through various storage modes; such as atomic spacing and bonding, atomic vibrations, and electron or magnetic ordering. The new technique uses advances in synchronized infra-red and x-ray laser pulses along with a large area position sensitive x-ray detector, to make x-ray scattering movies that track the response of the material from the moment of excitation. Infra-red light excites electrons and the x-rays measure the vibrational wave length and frequency where electron charge distortions couple strongly to changes in the atomic vibrations. Short-lived transient states can be excited and measured and help determine how energy flows on atomic length scales. The time-domain measurements are a direct way to follow the excitations of solids and the flow of energy well away from their “home” positions and ground state.
Department of Energy, Office of Science, Basic Energy Sciences program, for both the research and the use of the Linac Coherent Light Source user facility at SLAC.
M. Trigo et al., “Fourier-transform inelastic X-ray scattering from time- and momentum-dependent phonon–phonon correlations.” Nature Physics 9, 790 (2013).
Kristin Manke | newswise
High-precision magnetic field sensing
05.12.2016 | ETH Zurich
Energy hybrid: Battery meets super capacitor
01.12.2016 | Technische Universität Graz
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Information Technology
05.12.2016 | Earth Sciences