A shape-induced orientation phase within 3D nanocrystal solids

Designing nanocrystal (NC) materials aims at obtaining superlattices that mimic the atomic structure of crystalline solids. In such atomic systems, spatially anisotropic orbitals determine the crystalline lattice type. Similarly, in NC systems the building block anisotropy defines the order of the final solid: here, the NC shape governs the final superlattice structure. Yet, in contrast to atomic systems, NC shape-anisotropy induces not only positional, but also orientational order, ranging from full rotational disorder to a stable, fixed alignment of all NCs. This orientational relation is of special interest, as it determines to what extent atomically coherent connections between NCs are possible, thereby enabling complete wave function delocalization within the NC solid.
In addition to predicting the final NC orientation and position structure, the realization of NC materials demands a controllable fabrication process such that the designed order can be produced. Generally, such highly ordered NC superstructures are achieved through solvent evaporation induced self‐assembly on hard substrates. For applications where the 2D nature of this substrates process is limiting, nonsolvent into solvent diffusion, a technique commonly used to grow single crystals of dissolved molecules, is an attractive option. However, the precise influence of self-assembly parameters on the final superlattice outcome remains unknown. In this work, the researchers posed two closely related questions regarding the design of novel free-standing NC materials: (i) how can the NC self-assembly process be controlled to yield highly ordered free-standing supercrystals and (ii) what is the detailed positional and orientational order within the NC solid? A multidisciplinary team of collaborators, including the Austrian Small Angle X-ray Scattering (SAXS) beamline at Elettra, approached this challenge by a combined experimental and computational strategy.

>Read more on the Elettra Sincrotrone Trieste website

Image: Self‐assembly of 3D colloidal supercrystals built from faceted 20 nm Bi nanocrystals is studied by mens of in-situ synchrotron X‐ray scattering, combined with Monte Carlo simulations. 

New hutches installed as CHESS-U takes shape

The construction portion of the CHESS-U upgrade is nearing completion as teams work to assemble the last of the experimental hutches. While there is still plenty of work to be done, the preparation for becoming a true 3rd-generation lightsource is paying off.

In early 2019, CHESS-U will have an increased energy of the electron beam, from 5.3 to 6.0 GeV, double the current from 100 to 200 mA, and reduction of the horizontal emittance of the x-ray beam from 100nm to 30nm.
While these high energy x-rays will soon benefit researchers from around the world, new hutches are currently being built to contain and control the beam from the new undulator sources being installed. These hutches, or light-tight experimental rooms, will contain the x-rays by using multiple layers of lead for the walls and ceilings with additional shielding at the seams.

The design and installation of these hutches has been carefully coordinated. As utilities, cables and HVAC systems start to enter each room, it is worth noting the clever design that was used in order to retain the radiation-tight rooms. While safety was definitely at the forefront of the engineers’ minds, the ability to streamline the installation process was deliberately considered, and has since proven useful to compensate for any unavoidable delays.

>Read more on the CHESS website

Image: Kurt McDonald, CHESS Operator, helps install a new hutch for Sector 2. The modular design of the hutches has allowed for quicker installation. 

 

X-rays uncover a hidden property that leads to failure in a lithium-ion battery material

Experiments at SLAC and Berkeley Lab uproot long-held assumptions and will inform future battery design.

Over the past three decades, lithium-ion batteries, rechargeable batteries that move lithium ions back and forth to charge and discharge, have enabled smaller devices that juice up faster and last longer.
Now, X-ray experiments at the Department of Energy’s SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory have revealed that the pathways lithium ions take through a common battery material are more complex than previously thought. The results correct more than two decades worth of assumptions about the material and will help improve battery design, potentially leading to a new generation of lithium-ion batteries.

An international team of researchers, led by William Chueh, a faculty scientist at SLAC’s Stanford Institute for Materials & Energy Sciences and a Stanford materials science professor, published these findings today in Nature Materials.
“Before, it was kind of like a black box,” said Martin Bazant, a professor at the Massachusetts Institute of Technology and another leader of the study. “You could see that the material worked pretty well and certain additives seemed to help, but you couldn’t tell exactly where the lithium ions go in every step of the process. You could only try to develop a theory and work backwards from measurements. With new instruments and measurement techniques, we’re starting to have a more rigorous scientific understanding of how these things actually work.”

>Read more on the SLAC website

Image: When lithium ions flow into the battery’s solid electrode – illustrated here in hexagonal slices – the lithium can rearrange itself, causing the ions to clump together into hot spots that end up shortening the battery lifetime.
Credit: Stanford University/3Dgraphic

Diamond’s light illuminates our Anglo-Saxon heritage

Oakington is a small, village seven miles north-west of Cambridge. Archaeological finds in the area suggest that there may have been a settlement here in the Stone Age. In 1926, horticulturalist Alan Bloom was digging at his new nursery in Oakington when he uncovered three early Anglo-Saxon burials. In the 1990s, Cambridge County Council’s Archaeological Field Unit uncovered 24 more burials, which had been discovered during the construction of a children’s playground.
Wondering what else was hidden under the Fens, archaeologists from Oxford Archaeology East (then known as CAMARC) found 17 more burials in 2006/7. And in 2010/11, a further 27 burials were found in new trenches around the playground, including the remains of children, which are rare finds from this period. The most recent excavations were part of the ‘Bones without Barriers’ project, which encourages community communication and participation.

Innovative educational programs at Canadian Light Source

NSERC PromoScience awards $125K to innovative educational programs at Canadian Light Source.

The Canadian Light Source at the University of Saskatchewan has been awarded $125,000 by NSERC’s PromoScience program, to deliver innovative educational programs expected to reach students in over 100 schools across Canada.
PromoScience funding will enable teachers and students to perform hands-on research addressing real-world issues, through existing and new programs.

A new initiative, the Trans-Canadian Research & Environmental Education (TREE) project, will allow students from even the most remote communities across Canada to participate in a national research program in partnership with the Mistik Askiwin Dendrochronology (MAD) Lab at the University of Saskatchewan, using tree cores to study the environmental history of their community.

In an unprecedented collaboration between research and education, students will gather tree core samples and mail them to the CLS, where scientists will examine their chemical signatures while live streaming with the students who collected each sample. Teaching resources will help students to make sense of the data and to compare with other student samples from across the country, in order to understand how chemical changes in different tree cores correlate to their community’s environmental history.

“Students will learn about the life and nutrient cycles of trees, the trees’ ability to capture information in rings, and the nutrients in soil by working through modules and activities designed to engage students in the areas of STEM and traditional knowledge,” said Tracy Walker, Education Programs Lead at the CLS.

>Read more on the Canadian Light Source website

X-rays reveal L-shape of scaffolding protein

Structural biologists discover unexpected results at PETRA III at DESY in Germany.

An investigation at DESY’s X-ray light source PETRA III has revealed a surprising shape of an important scaffolding protein for biological cells. The scaffolding protein PDZK1 is comprised of four so-called PDZ domains, three linkers and a C-terminal tail. While bioinformatics tools had suggested that PDZK1’s PDZ domains and linkers would behave like beads on a string moving around in a highly flexible manner, the X-ray experiments showed that PDZK1 has a relatively defined L-shaped conformation with only moderate flexibility. The team led by Christian Löw from the Centre for Structural Systems Biology CSSB at DESY and Dmitri Svergun from the Hamburg branch of the European Molecular Biology Laboratory EMBL report their results in the journal Structure.

Similar to metal scaffolding which provides construction workers with access points to a building, scaffolding proteins mediate interactions between proteins situated on the membrane of the human cell. While the molecular structure of each of PDZK1’s four individual PDZ domains has been solved using X-ray crystallography and NMR spectroscopy, the overall arrangement of the domains in the protein as well as their interactions was not yet understood.

>Read more on the PETRA III at DESY website

Image: Artistic shape interpretation of the scaffolding protein PDZK1. (Credit: Manon Boschard)tistic shape interpretation of the scaffolding protein PDZK1.
Credit: Manon Boschard

Ultralow-fluence for phase-change process

Ultrafast active materials with tunable properties are currently investigated for producing successful memory and data-processing devices. Among others, Phase-Change Materials (PCMs) are eligible for this purpose. They can reversibly switch between a high-conductive crystalline state (SET) and a low-conductive amorphous state (RESET), defining a binary code. The transformation is triggered by an electrical or optical pulse of different intensity and time duration. 3D Ge-Sb-Te based alloys, of different stoichiometry, are already employed in DVDs or Blu-Ray Disks, but they are expected to function also in non-volatile memories and RAM. The challenge is to demonstrate that the scalability to 2D, 1D up to 0D of the GST alloys improves the phase-change process in terms of lower power threshold and faster switching time. Nowadays, GST thin films and nanoparticles have been synthetized and have beenshown to function with competitive results.
A team of researchers from the University of Trieste and the MagneDyn beamline at Fermi demonstrated the optical switch from crystalline to amorphous state of Ge2Sb2Te5nanoparticles (GST NPs) with size <10 nm, produced via magnetron sputtering by collaborators from the University of Groeningen. Details were reported in the journal Nanoscale.
This work aims at showing the very low power limit of an optical pulse needed to amorphize crystalline Ge2Sb2Te5 nanoparticles. Particles of 7.8 nm and 10.4 nm diameter size were deposited on Mica and capped with ~200nm of PMMA. Researchers made use of a table-top Ti:Sapphire regenerative amplified system-available at the IDontKerr (IDK) laboratory (MagneDyn beamline support laboratory) to produce pump laser pulses at 400 nm, of ~100 fs and with a repetition rate from 1kHz to single shot.

>Read more on the Elettra Sincrotrone Trieste website

Image (extract): Trasmission Electron Microscopy image of the nanoparticles sample. Ultafast single-shot optical process with fs-pulse at 400 nm. Microscope images of amorphized and amorphized/ablated areas obtained on the nanoparticles sample. Comparison of amorphization threshold fluences between thin films and nanoparticles cases.
Please see here the entire image.

Snaphot of molecular mechanism at work in lethal virus

X-ray crystallography at the Australian Synchrotron contributed to major research findings.

Data collected on the macromolecular crystallography beamlines at the Australian Synchrotron has contributed to major research findings on two deadly viruses, Hendra and Nipah, found in Australia, Asia and Africa. The viruses can be transmitted to humans not directly by the bat which is the natural carrier but by an infected animal like horses or pigs.

Beamline scientist, Dr David Aragao (pictured above), a co-author on the paper in Nature Communications, said that obtaining a clear motion picture of key biological process at the molecular level of viruses is often not available with current biomedical techniques.
“However, using X-ray crystallography from data collected on both MX1 and MX2 beamlines at the Australian Synchrotron, we were able to obtain  8  ‘photograph-like’ snapshots of the molecular process that allows the Hendra and Nipah virus to replicate.“

Two authors of the paper, PhD students Kate Smith and Sofiya Tsimbalyuk, who are co-supervised by Aragao and his collaborator Professor of Biochemistry Jade Forwood of the Graham Centre for Agricultural Innovation Charles Sturt University, used the Synchrotron extensively collecting multiple data sets that required extensive refinements over two years to isolate the mechanism of interest.

>Read more on the Australian Synchrotron website

Image: Beamline scientist, Dr David Aragao.

New cryo-EM Collaboration

UK set to be global leader in providing large-scale industrial access to Cryo-EM for drug discovery thanks to new collaboration.


Thermo Fisher Scientific and Diamond Light Source are creating a step change for life sciences sector, a one-stop shop for structural biology and one of largest cryo-EM sites in the world.
An agreement to launch a new cryo-EM capability for use in the life sciences industry sector by Thermo Fisher Scientific, one of the world leaders in high-end scientific instrumentation, and Diamond Light Source, the UK’s national synchrotron and one of the most advanced scientific facilities in the world, was announced today ahead of the official opening of the new national electron bio-imaging centre (eBIC) which will be held at Diamond on September 12th 2018.

This announcement confirms Diamond as one of the major global cryo-EM sites embedded with an abundance of complementary synchrotron-based techniques, and thereby, provides the life sciences sector with an offer not available anywhere else in the world.

Professor Dave Stuart, Life Sciences Director at Diamond and MRC Professor of Structural Biology at the University of Oxford, Department of Clinical Medicine, says, “Access to 21st century scientific tools to push the boundaries of scientific research is essential for both academia and industry, and what we have created here at Diamond is truly unique in the world in terms of size and scale. The new centre offers the opportunity for almost real-time physiology, capturing proteins in action at cryo-temperatures by flash-freezing them at various stages. What Diamond has created with eBIC is an integrated facility for structural biology, which will accelerate R&D for both industry and academic users. The additional advanced instruments made available by Thermo Fisher will position the UK as a global leader in providing large-scale industrial access to cryo-EM for drug discovery research. Our new collaboration provides a step change in our offer for industry users and helps ensure that R&D remains in the UK.”

>Read more on the Diamond Light Source website

Image: Close up sample loading Krios I.

ESRF-EBS confirmed as landmark in ESFRI roadmap

On 11 September 2018, in Vienna, the European Strategy Forum on Research Infrastructures (ESFRI) presented the ESFRI Roadmap 2018 on Large Scale Research Infrastructures.

The ESRF-Extremely Brilliant Source (ESRF-EBS) is confirmed as a major landmark project. ESRF-EBS is a 150-million euro facility upgrade, over the period 2015-2022. With the construction of a brand-new storage ring, ESRF-EBS will be the world’s first high-energy fourth-generation synchrotron light source.

This year, the ESRF celebrates its 30th anniversary: 30 years of scientific discoveries, 30 years of innovation. In 1988, the ESRF made history as the world’s first third-generation synchrotron light source, producing X-rays 100 billion times brighter than the X-rays used in hospitals and providing unrivalled opportunities for scientists in the exploration of materials and living matter. For 30 years, the ESRF has aligned success after success, breaking records for its scientific output with over 30 000 publications and four Nobel prize laureates, as well as for the brilliance and stability of its X-ray beams. Today, the ESRF continues to lead the way with the Extremely Brilliant Source, a 150M€ project, funded by the 22 partner countries of the ESRF.

>Read more on the European Synchrotron (ESRF) website

A new approach for finding Alzheimer’s treatments

Considering what little progress has been made finding drugs to treat Alzheimer’s disease, Maikel Rheinstädter decided to come at the problem from a totally different angle—perhaps the solution lay not with the peptide clusters known as senile plaques typically found in the brains of Alzheimer’s patients, but with the surrounding brain tissue that allowed those plaques to form in the first place.
It was a novel approach that paid off for Rheinstädter and his team of researchers from McMaster University who used the Canadian Light Source in Saskatoon as part of a study of the effect various compounds have on membranes in brain tissue and the possible impact on plaque formation.

“Alzheimer’s disease has interested me for a long time,” said Rheinstädter, a professor in the Department of Physics and Astronomy and the Origins Institute at McMaster. “It is something almost every Canadian will be affected by in their lives.”

>Read more on the Canadian Light Source website

Image: Adam Hitchcock, Adree Khondker and Maikel Rheinstädter.