Publications de Christopher Milne

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The transfer of charge at the molecular level plays a fundamental role in many areas of chemistry, physics, biology and materials science. Today, more than 60 years after the seminal work of R. A. Marcus, charge transfer is still a very active field of res ...

Ultrafast electron delocalization induced by a femtosecond laser pulse is a well-known process in which electrons are ejected from the ions within the laser pulse duration. However, very little is known about the speed of electron localization out of an el ...

A von Hamos geometry based wavelength dispersive spectrometer combined with an in situ reactor cell has been developed to measure non-resonant sulfur K alpha emission for the in situ speciation of low concentrations of sulfur. The spectrometer operates at ...

The strength of the electron-phonon coupling parameter and its evolution throughout a solid's phase diagram often determines phenomena such as superconductivity, charge- and spin-density waves. Its experimental determination relies on the ability to distin ...

OLED technology beyond small or expensive devices requires light-emitters, luminophores, based on earth-abundant elements. Understanding and experimental verification of charge transfer in luminophores are needed for this development. An organometallic mul ...

We discuss two techniques of ultrafast X-ray science implemented at synchrotrons with application to the study of the real-time dynamics of chemical systems in solution. Time-resolved X-ray scattering and absorption offer complementary ways to study geomet ...

We present a static and picosecond X-ray absorption study at the Cu K-edge of bis(2,9-dimethyl-1,10-phenanthroline)copper(I) (Cu(dmp)(2); dmp = 2,9-dimethyl-1,10-phenanthroline) dissolved in acetonitrile and dichloromethane. The steady-state photolumi ...

We present a Wavelet transform analysis for the X-ray absorption spectra of molecules. In contrast to the traditionally used Fourier transform approach, this analysis yields a 2D correlation plot in both R- and k-space. As a consequence, it is possible to ...

Quantum efficiency studies for various laser wavelengths and various technical metal surfaces were carried out in a dedicated unbaked vacuum chamber in the absence of a significant electrical field. Copper, magnesium, aluminum, and aluminum-lithium photoca ...

We review our recent activity in the field of photo-induced structural dynamics in crystalline solids studied using femtosecond X-ray diffraction techniques. ...

We present a complete characterization of the unit cell dynamics of a laser-excited tellurium crystal using femtosecond x-ray diffraction. The analysis offers a quantitative measure of the unit cell dynamics without making any assumptions on the symmetry o ...

The timescales for structural changes in a single crystal of bismuth after excitation with an intense near-infrared laser pulse are studied with femtosecond pump-probe X-ray diffraction. Changes in the intensity and reciprocal-lattice vector of several ref ...

Describing the nature and structure of molecular excited states is important in order to understand their chemical reactivity and role as intermediates in photochemical reactions. The recent implementation of x-ray absorption spectroscopy in the ultrafast ...

X-ray absorption spectra of fac-[ReBr(CO)(3)(bpy)] near the Re L-3- and Br K-edges were measured in a steady-state mode as well as time-resolved at 630 ps after 355 nm laser pulse excitation. Relativistic spin-orbit time-dependent density functional theory ...

Picosecond and femtosecond X-ray absorption spectroscopy is used to probe the changes of the solvent shell structure upon electron abstraction of aqueous iodide using an ultrashort laser pulse. The transient L-1,L-3 edge EXAFS at 50 ps time delay points to ...

We directly measure by femtosecond time-resolved x-ray diffraction the E-g symmetry coherent phonon excited in bismuth by a strong optical pulse. The magnitude of the E-g mode observed is 0.2 pm peak-to-peak, compared against the 2.7-pm initial displacemen ...

Squeezed states are quantum states of a harmonic oscillator in which the variance of two conjugate variables each oscillate out of phase. Ultrafast optical excitation of crystals can create squeezed phonon states, where the variance of the atomic displacem ...

We use femtosecond x-ray diffraction to probe directly the structural dynamics of a charge ordered and orbitally ordered thin film of La0.42Ca0.58MnO3 initiated by an ultrafast optical pulse. At low excitation fluences we observe the displacive excitation ...

Identifying the intermediate species along a reaction pathway is a first step towards a complete understanding of the reaction mechanism, but often this task is not trivial. There has been a strong on-going debate: which of the three intermediates, the CHI ...

Metallica: A large contraction of the PtPt bond in the triplet excited state of the photoreactive [Pt2(P2O5H2)4]4- ion is determined by time-resolved X-ray absorption spectroscopy (see picture). The strengthening of the PtPt interaction is accompanied by a ...

Christopher Milne

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Charge migration and charge transfer in molecular systems

Ultrafast electron localization in the EuNi2(Si0.21Ge0.79)(2) correlated metal

A von Hamos spectrometer for in situ sulfur speciation by non-resonant sulfur K alpha emission spectroscopy

Temperature-dependent electron-phonon coupling in La_{2−x}Sr_{x}CuO_{4} probed by femtosecond x-ray diffraction

Taking a snapshot of the triplet excited state of an OLED organometallic luminophore using X-rays

Ultrafast X-ray Science: Structural Transients in Solution

Solvent Induced Luminescence Quenching: Static and Time-Resolved X-Ray Absorption Spectroscopy of a Copper(I) Phenanthroline Complex

A wavelet analysis for the X-ray absorption spectra of molecules

Quantum efficiency of technical metal photocathodes under laser irradiation of various wavelengths

Ultrafast Structural Dynamics in Condensed Matter

Full Reconstruction of a Crystal Unit Cell Structure during Coherent Femtosecond Motion

Non-equilibrium phonon dynamics studied by grazing-incidence femtosecond X-ray crystallography

Retrieving photochemically active structures by time-resolved EXAFS spectroscopy

Re and Br X-ray Absorption Near-Edge Structure Study of the Ground and Excited States of [ReBr(CO)(3)(bpy)] Interpreted by DFT and TD-DFT Calculations

Probing the Transition from Hydrophilic to Hydrophobic Solvation with Atomic Scale Resolution

Direct observation of non-fully-symmetric coherent optical phonons by femtosecond x-ray diffraction

Directly Observing Squeezed Phonon States with Femtosecond X-Ray Diffraction

Ultrafast Structural Phase Transition Driven by Photoinduced Melting of Charge and Orbital Order

Identifying the major intermediate species by combining time-resolved X-ray solution scattering and X-ray absorption spectroscopy

Structural determination of photochemically active diplatinum molecule by time-resolved EXAFS spectroscopy