Related papers: Revealing timescale-dependent oxygen vacancy distr…
In this series of three papers we present results from a combined experimental and theoretical effort to quantitatively describe capacitively coupled radio-frequency discharges in oxygen. The particle-in-cell Monte-Carlo model on which the…
The impedance of a Li-ion battery contains information about its state of charge (SOC), state of health (SOH) and remaining useful life (RUL). Commonly, electrochemical impedance spectroscopy (EIS) is used as a nonparametric data-driven…
We report a novel mechanism, consisting of redistribution of valence electrons near the Fermi level, during interactions of intense femtosecond X-ray pulses with a Co/Pd multilayer. The changes in Co 3d valence shell occupation were…
Realizing reversible reduction-oxidation (Redox) reactions of lattice oxygen in batteries is a promising way to improve the energy and power density. However, conventional oxygen absorption spectroscopy fails to distinguish the critical…
Linking electrode microstructure to electrochemical performance is essential for optimizing Li-ion batteries. However, this requires mechanistic 4D observations at ultimate spatio-temporal scales, which remains elusive. Here we demonstrate…
Phase transitions are governed by both intrinsic and extrinsic heterogeneities, yet capturing their spatio-temporal dynamics remains a challenge. While ultrafast techniques track phase changes on femtosecond timescales, the spatial…
Averaged plasma parameters such as electron distribution function and electron density are determined by characterization of high frequency (2.4 GHz) nitrogen-plasma using both experimental methods, namely optical emission spectroscopy…
Solid oxide fuel cells (SOFCs) are becoming increasingly important due to their high electrical efficiency, the flexible choice of fuels and relatively low emissions of pollutants. However, the increasingly growing demands for…
We present a femtosecond time-resolved optical spectroscopy (TRS) as an experimental tool to probe the changes in the low energy electronic density of states as a result of short and long range charge density wave order. In these…
X-ray absorption spectroscopy (XAS) is a commonly-employed technique for characterizing functional materials. In particular, x-ray absorption near edge spectra (XANES) encodes local coordination and electronic information and machine…
X-ray diffraction from molecules in the ground state produces an image of their charge density, and time-resolved X-ray diffraction can thus monitor the motion of the nuclei. However, the density change of excited valence electrons upon…
Time-resolved x-ray scattering (TRXS) measures internuclear separations in a molecule following laser-induced photoexcitation. The molecular dynamics induced by the excitation laser may lie on one or several bound or dissociative electronic…
This work developed an accurate and robust absorption-based method for spatially resolved measurements of gas temperatures in flames and reacting flows, with typical single-measurement uncertainties on the order of 1\%. This method exploits…
The development of high-brightness free-electron lasers (FEL) has revolutionised our ability to create and study matter in the high-energy-density (HED) regime. Current diagnostic techniques have been very successful in yielding information…
Single-shot ultrafast absorbance spectroscopy based on the frequency encoding of the kinetics is analyzed theoretically and implemented experimentally. In Part II of the series, arbitrary thickness sample is analysed theroretically. The…
We use an x-ray free-electron laser to study the ultrafast lattice dynamics following above band-gap photoexcitation of the incipient ferroelectric potassium-tantalate, \kto. % We use ultrafast near-UV (central wavelength 266\,nm and 50 fs…
We propose the use of a frequency-dependent photothermal measurement as a complement to light-flash, i.e. time-dependent, measurements to determine the through-plane thermal diffusivity of small, thin samples, e.g. semiconducting polymers…
The kinetics of the oxygen reduction reaction (ORR) on the practical air cathode in a Lithium air cell, which is conventionally composed of porous carbon with or without catalysts supported on it, was investigated. The mechanism and…
Femtosecond X-ray irradiation of solids excites energetic photoelectrons that thermalize on a timescale of a few hundred femtoseconds. The thermalized electrons exchange energy with the lattice and heat it up. Experiments with X-ray…
It is demonstrated that velocity selective optical pumping/saturation resonances of reduced absorption in a Rb vapor nanocell with thickness \textit{L=} $\lambda $, 2$\lambda $, and 3$\lambda $ (resonant wavelength $\lambda $ = 780 nm)…