The ESRF/ILL International Student Summer Programme is helping students to take one step nearer to their dreams. Viktor Radermacher has blisters on his hands but a huge smile on his face. The blisters are from carrying the 8kg case containing a precious dinosaur fossil all the way from South Africa, the smile because it’s the first time away from his home country and he’s living the dream that has inhabited him since the age of 2. He is, at last, working with dinosaurs. In fact, he is using the most advanced techniques available to palaeontologists today to scan fossils using the ESRF’s ultra bright X-rays.
Ghost imaging is an indirect method in which most of the X-rays used for the experiment never actually interact with the sample. The first demonstration of X-ray ghost imaging has been carried out at beamline ID19. The method uses two copies of the same speckled beam and the image is retrieved indirectly by correlating the two measured signals. This experiment could lead to the development of low-dose medical X-ray diagnostics and diffraction-imaging at free electron lasers.
Operando X-ray tomographic microscopy (SRXTM) and scanning X-ray diffraction (SXRD) have been combined for the first time to study dynamic processes in a lithium ion battery. This combination of techniques allowed the lithiation processes to be tracked throughout the electrodes on different length scales: the dynamic distribution of crystallographic phases was analysed using SXRD, while SRXTM data was used to probe volumetric changes and understand the interplay of different kinetic limitations.
Two-dimensional systems have recently emerged as very promising candidates for future electronic devices. An ordered 2D array of nanocrystals can be created by letting nanocrystals self-assemble and connect at a liquid surface. This new structure shows excellent long range order on both the nanocrystal and atomic level. Experiments at beamline ID10 revealed how the nanocrystals order themselves and ‘click together’ to produce beautiful 2D superlattices.
Preferred crystal orientation (crystallographic texture) is a common phenomenon in many complex micro- and nanocrystalline materials of biological and synthetic origin. Conventionally, texture determination by XRD involves sample 2D diffraction images combined into 3D information by sample rotation. We have shown that the photon energies (“X-ray colours”) in a white X-ray beam can be exploited to gain direct 3D crystallographic information in texture measurements. The functionality of the method was demonstrated on carbon fibres and lobster cuticle.
Super elastic nickel-titanium (NiTi) alloys can tolerate large deformations due to a stress-induced martensitic transformation. When NiTi wire is stretched, a propagating macroscopic transformation front moves along the wire, separating transformed and untransformed regions, unlike other materials which deform homogenously. 3D-XRD stress tomography provided scientists with stress and strain tensors in austenite grains near this propagating front, and they could reconstruct a complete 3D picture of the front using digital image correlation and finite element modelling.
A remarkably strong and anisotropic spin-phonon coupling was discovered for the ferromagnetic semiconductor europium monoxide through synchrotron experiments, inelastic X-ray scattering and nuclear inelastic scattering, and density functional theory. This discovery paves the way towards the design of spintronics devices with new functionalities.
Through an experiment at the ESRF, scientists from Brookhaven National Laboratory have found evidence for propagating in-plane transverse phonon modes in a DPPC lipid membrane. These transverse phonon modes exhibit phononic gaps upon temperature increase, providing a direct signature of the existence of transient voids caused by short-lived lipid density fluctuations that mediate solute permeation across the membrane. The finding supports the mechanism of passive transport through entropic expulsion of the solute from higher to lower lipid density regions across the membrane.
On 28th June, the European Synchrotron welcomed Mr Dmitry LIVANOV, Minister of Education and Science of the Russian Federation, on the occasion of the 65th ESRF international Council meeting.
The existence of single-atom magnets has been proven by X-ray magnetic circular dichroism. Monodisperse holmium atoms adsorbed on a nonmagnetic MgO thin film display magnetic hysteresis up to a temperature of 30 K and with magnetic relaxation time of the order of 1500 s. This stability is exceptional for such tiny structures. This study unveils key factors to improve the stability of atom-sized magnets in a solid state environment.