This work provides an up-to-date account of the use electron-volt neutron spectroscopy in materials research. is a growing area science, capitalising upon unique insights provided by epithermal neutrons on behaviour and properties increasing number complex materials. As such, present builds aims scope previous contribution to this journal back 2005, whose primary focus was detailed description theoretical foundations technique their application fundamental systems [see Andreani et al., Adv....

The VESUVIO spectrometer at the ISIS pulsed neutron and muon source is a unique instrument amongst those available facilities. This only inverted-geometry accessing values of energy wavevector transfer above tens eV ${\mathring{\rm A}}^{-1}$ , respectively, where deep inelastic scattering experiments are routinely performed. As such, procedure base technique has been previously described in an article published by this journal (Mayers Reiter 2012 Meas. Sci. Technol. 23 045902). recently...

The Photosystem I (PS I) reaction center contains two branches of nearly symmetric cofactors bound to the PsaA and PsaB heterodimer. From x-ray crystal structure it is known that Trp697PsaA Trp677PsaB are π-stacked with head group phylloquinones H-bonded Ser692PsaA Ser672PsaB, whereas Arg694PsaA Arg674PsaB involved in a network side groups connects binding environments FX. mutants W697FPsaA, W677FPsaB, S692CPsaA, S672CPsaB, R694APsaA, R674APsaB were constructed characterized. All grew...

We apply a unique sequence of structural and dynamical neutron-scattering techniques, augmented with density-functional electronic-structure calculations, to establish the degree polymorphism in an archetypal hydrogen-bonded system - crystalline formic acid. Using this combination experimental theoretical hypothesis by Zelsmann on coexistence β1 β2 phases above 220 K is tested. Contrary postulated scenario proton-transfer-driven phase coexistence, emerging picture one quantitatively...

Neutron spectroscopy and first-principles calculations unveil the quantum character of atomic motions in solid acid CsHSO₄.

Porous organic cages (POCs) are nanoporous materials composed of discrete molecular units that have uniformly distributed functional pores. The intrinsic porosity these structures can be tuned accurately at the nanoscale by altering size porous molecules, particularly to an optimal 3.6 Å, harness kinetic quantum sieving effect. Previous research on POCs for isotope separation has predominantly centered differences in quantities adsorbed isotopes. However, nuclear effects also contribute...

Here, we report the possible origin of natural and magnetic field induced polar order near room temperature (RT) in $\mathrm{Pr}{\mathrm{Fe}}_{1/2}{\mathrm{Cr}}_{1/2}{\mathrm{O}}_{3}$. The temperature-dependent Raman spectroscopy (RS) synchrotron x-ray diffraction experiments disregard any change structure at low temperatures, which is not compatible with emergence ferroelectricity this sample. Further, inelastic neutron scattering, Compton resonance transmission analysis field-dependent RS...

Theoretical nuclear momentum distributions for solid lithium hydride and deuteride are presented. Electronic-structure calculations were performed within the framework of plane-wave density functional theory, followed by computation phonon-dispersion relations vibrational densities states. The generalized-gradient-approximation Perdew, Burke, Ernzerhof was used in these first-principles calculations. Our computational results compared with existing neutron Compton scattering inelastic...

The adsorption of molecular hydrogen (H2) in the alkali-graphite intercalate KC24 has been studied using simultaneous neutron diffraction and Compton scattering. Neutron scattering data for (H2)xKC24 system (x = 0–2.5) were measured at T 1.5 K as a function relative orientation between beam c-axis. Synchronous with above proton-recoil measurements, high-resolution patterns back-scattering geometry. From these intrinsic mosaicity Papyex-based was determined to be ∼15°...

Neutron Compton scattering experiments on crystalline lithium hydride and deuteride are presented compared with existing experimental data first-principles predictions. With currently available instrumentation, these measurements demonstrate sufficient mass selectivity for studies of nuclear-momentum distributions protons, deuterons, using forward backscattering geometries. In both materials, spectral discrimination lithium-recoil features is highest in geometry, although isolation also...

We discuss ongoing methodological developments underpinning the determination of nuclear-momentum distributions from mass-resolved neutron Compton data lightweight materials. To this end, two systems are considered in detail, namely, lithium hydride (including its deuterated counterpart) and squaric acid, an organic antiferroelectric material containing hydrogen, carbon, oxygen. Beyond usual case proton, our approach enables direct access to detailed line shape information associated with...

We present an overview of ongoing developments in epithermal neutron spectroscopy using the VESUVIO+ beam line at ISIS Facility. In its current incarnation, provides a suitable platform for further and much-needed progress judicious exploitation neutrons pulsed spallation source, as well constitutes necessary milestone towards next-generation station Epithermal Thermal Neutron Analysis, hereafter ETNA. particular, we discuss recent improvements capability relative to predecessor VESUVIO....

We present time-resolved neutron-imaging results on the ortho- to para-hydrogen conversion in presence of a nanoparticle powder ferromagnetic catalyst γ-Fe2O3. In particular, we were able characterize rate as function time and position molecular hydrogen with respect catalyst. Results are reported for liquid solid at 15 10 K, respectively. discuss how newly generated poisons catalyst, thus slowing process preventing full large quantities condensed hydrogen, underline performance critically...

Application of neutron Compton scattering, which operates in the attosecond time scale, to (a) equimolar ${\mathrm{H}}_{2}\ensuremath{-}{\mathrm{D}}_{2}$ mixture and (b) mixed-isotope system HD (liquids, both at 20 K), reveals a strong anomalous shortfall (about 30%) ratio $R={\ensuremath{\sigma}}_{H}∕{\ensuremath{\sigma}}_{D}$ H D cross sections. This striking effect is similar that observed liquid ${\mathrm{H}}_{2}\mathrm{O}\ensuremath{-}{\mathrm{D}}_{2}\mathrm{O}$ mixtures [C. A....

A calculation of nuclear momentum distribution liquid and solid hydrogen fluoride was performed. In both systems, density functional theory generalized gradient approximation Perdew, Burke, Ernzerhof used for the calculation: fluoride, using an atom centered basis set isolated molecule with optimized geometry, plane-wave sets on orthorhombic crystal cell. For a semiclassical approach adopted vibrational contribution to obtained from translational rotational contributions calculated...

This paper describes ongoing efforts to implement the reduction and analysis of neutron Compton scattering data within MANTID framework. Recently, extensive work has been carried out integrate bespoke routines written for VESUVIO with While programs described in this document are designed replicate functionality Fortran Genie already use, most them have from scratch not based on original code base.

The VESUVIO spectrometer at the ISIS pulsed neutron and muon source is an epithermal thermal station requiring a software suite able to tackle analysis of experimental data from several techniques. We present update on tools available within MANTID environment for treatment Compton scattering data, we discuss new strategies profiles momentum distributions that provide robustness scientific studies based this technique.

This work introduces the use of mass-selective neutron spectroscopy as an analytical tool for quantitative and non-destructive detection hydrogen in bulk media. To this end, systematic measurements have been performed on a series polyethylene standards known thickness density, order to establish optimal data-acquisition protocols well associated limits quantitation. From analysis, we conclude that state-of-the-art epithermal-neutron instrumentation enables aeral molar densities μmol cm-2...