Beryllium configuration with neighbouring oxygen atoms revealed

High-pressure experiments prove 50-year-old theoretical prediction.

In high-pressure experiments at DESY’s X-ray light source PETRA III, scientists have observed a unique configuration of beryllium for the first time: At pressures nearly a million times the average atmospheric pressure, beryllium in a phosphate crystal acquires six neighbouring atoms instead of the usual four. This six-fold coordination had been predicted by theory more than 50 ago, but could not be observed until now in inorganic compounds. DESY scientist Anna Pakhomova and her collaborators report their results in the journal Nature Communications.
“Originally, chemistry textbooks stated that elements like beryllium from the second period of the periodic table could never have more than four neighbours, due to their electron configuration”, explains Pakhomova. “Then around 50 years ago theorists discovered that higher coordinations could actually be possible, but these have adamantly evaded experimental proof in inorganic compounds.” Inorganic compounds are typically those without carbon – apart from a few exceptions like carbon dioxide and carbon monoxide.

>Read more on the PETRA III at DESY website

Image: Transformation of the usual fourfold coordination of beryllium to five- and sixfold with increasing pressure. (Credit: DESY, Anna Pakhomova)

Helping people to hear

Using advanced techniques at the Canadian Light Source (CLS) at the University of Saskatchewan, scientists have created three-dimensional images of the complex interior anatomy of the human ear, information that is key to improving the design and placement of cochlear implants.
“With the images, we can now see the relationship between the cochlear implant electrode and the soft tissue, and we can design electrodes to better fit the cochlea,” said Dr. Helge Rask-Andersen, senior professor at Uppsala University in Sweden.
“The technique is fantastic and we can now assess the human inner ear in a very detailed way.”
The cochlea is the part of the inner ear that looks like a snail shell and receives sound in the form of vibrations. In cases of hearing loss, cochlear implants are used to bypass damaged parts of the ear and directly stimulate the auditory nerve. The implant generates signals that travel via the auditory nerve to the brain and are recognized as sound.
By imaging the soft and bony structures of the inner ear with implant electrodes in place, Rask-Andersen said the researchers were able to discover what the auditory nerve looks like in three dimensions, and to learn how cochlear implant electrodes behave inside the cochlea. This is very important when cochlear implants are considered for people with limited hearing.

>Read more on the Canadian Light Source website

Image: the inner ear

New device squeezes samples with 1.6 billion atmospheres per second

Simulating earthquakes and meteorite impacts in the lab.

A new super-fast high-pressure device at DESY’s X-ray light source PETRA III allows scientists to simulate and study earthquakes and meteorite impacts more realistically in the lab. The new-generation dynamic diamond anvil cell (dDAC), developed by scientists from Lawrence Livermore National Laboratory (LLNL), DESY, the European Synchrotron Radiation Source ESRF, and the universities of Oxford, Bayreuth and Frankfurt/Main, compresses samples faster than any similar device before. The instrument can turn up the pressure at a record rate of 1.6 billion atmospheres per second (160 terapascals per second, TPa/s) and can be used for a wide range of dynamic high-pressure studies. The developers present their new device, that has already proven its capabilities in various materials experiments, in the journal Review of Scientific Instruments.
“For more than half a century the diamond anvil cell or DAC has been the primary tool to create static high pressures to study the physics and chemistry of materials under those extreme conditions, for example to explore the physical properties of materials at the center of the Earth at 3.5 million atmospheres,” said lead author Zsolt Jenei from LLNL. To simulate fast dynamic processes like earthquakes and asteroid impacts more realistically with high compression rates in the lab, Jenei’s team, in collaboration with DESY scientists, now developed a new generation of dynamically driven diamond anvil cell (dDAC), inspired by the pioneering original LLNL design, and coupled it with the new fast X-ray diffraction setup of the Extreme Conditions Beamline P02.2 at PETRA III.

>Read more on the PETRA III at DESY website

Image: The new dynamic diamond anvil cell (dDAC) at the Extreme Conditions Beamline (ECB) at DESY’s X-ray source PETRA III.
Credit: DESY, Hanns-Peter Liermann

European XFEL plans ultrahigh-speed network connection to Poland

Data from experiments will also be processed at partner institute NCBJ in Otwock-Świerk.

European XFEL and the National Center for Nuclear Research (NCBJ) in Otwock-Świerk near Warsaw plan to establish the first ultrahigh-speed connection for research data between Germany and Poland. The aim is for the new Supercomputing Center at NCBJ to be used for the processing and analysis of data generated at the European XFEL. The dedicated network connection between the DESY Computer Center, which hosts European XFEL’s primary data, and NCBJ will feature a data transfer rate of 100 gigabits per second (Gbit/s). With the exception of the higher-speed connection to DESY, that is approximately 100 times faster than the current typical Internet connection between European XFEL and other research institutes, through which the transfer of data for an average experiment at the facility would take about a month. In comparison, household high-speed Internet connections can typically manage about 250 Mbit/s for a download. This makes this new connection at least 400 times faster.
For the installation of the new high-speed data connection, the German National Research and Education Network (DFN), the Supercomputing and Networking Center at the Institute for Bioorganic Chemistry in Poznań (PSNC), the Research and Academic Computer Network National Research Institute (NASK), and Deutsches Elektronen-Synchrotron (DESY) will also take part alongside European XFEL and NCBJ. At the end of May this year, the partners signed a Memorandum of Understanding that will serve as the basis and starting point for establishing the new high-speed connection. It can largely be built on existing technical infrastructure, but certain specific components will have to be added. For example, the connection between the German and Polish research networks will be enabled by the European University Viadrina in Frankfurt an der Oder and the neighbouring Polish city of Słubice.

>Read more on the European XFEL website

Image: At European XFEL at peak user operation times, up to a petabyte of data can be produced per week.
Credit:  European XFEL / Jan Hosan

Publication of the first scientific paper

June 1, 2019 marks a historically important accomplishment for SESAME, where the very first scientific paper presenting results using data obtained at SESAME’s X-ray absorption fine structure/X-ray fluorescence (XAFS/XRF) spectroscopy beamline was published in Applied Catalysis B: Environmental.

S: Bac et al. Applied Catalysis B: Environmental, 259, 2019, 117808 https://www.sciencedirect.com/science/article/pii/S0926337319305545

Synchrotron measurements performed at SESAME were carried out by the research group of Associate Professor Emrah Ozensoy (Bilkent University Chemistry Department and UNAM-National Nanotechnology Center Ankara, Turkey), in collaboration with the research group of Professor Ahmet Kerim Avcı (Boğaziçi University, Chemical Engineering Department, Istanbul, Turkey) and Dr Messaoud Harfouche (XAFS/XRF beamline scientist, SESAME, Allan, Jordan).
The paper entitled Exceptionally active and stable catalysts for CO2 reforming of glycerol to syngas is the outcome of a measurement campaign at SESAME in July 2018 and focuses on the catalytic valorization of a biomass waste material (i.e. glycerol) to obtain synthesis gas (or syngas, CO + H2). Glycerol is an important renewable feedstock for the large-scale catalytic production of synthetic liquid fuels through a process called Fischer-Tropsch synthesis. In the words of Emrah Ozensoy “XAFS/XRF experiments performed at SESAME were instrumental for us to understand the electronic structure of the Co/CoOx and Ni/NiOx nanoparticles serving as the catalytic active sites. Particularly, complementing the experimental data acquired in our labs with the results obtained at SESAME allowed us to examine the nature of the fresh catalysts and compare them with that of the spent catalysts obtained after the catalytic reaction, revealing crucial molecular-level insights regarding the catalytic aging and poisoning mechanisms.”

>Read more on the SESAME website

Image: Kerem Emre Ercan Some of the researchers who contributed to the publication and data acquisition (from left to right, Yusuf Koçak, Kerem E. Ercan, and M. Fatih Genişel)

Feeling the strain: shear effects in magnetoelectric switching

Diamond uncovers unexpected complexity that may aid magnetoelectric data storage devices.

The high resolution and wealth of data provided by an experiment at Diamond can lead to unexpected discoveries. The piezoelectric properties of the ceramic perovskite PMN-PT (0.68Pb(Mg1/3Nb2/3)O3–0.32PbTiO3) are widely used in commercial actuators, where the strain that is generated varies continuously with applied voltage. However, if the applied voltage is cycled appropriately then there are discontinuous changes of strain. These discontinuous changes can be used to drive magnetic switching in a thin overlying ferromagnet, permitting magnetic information to be written electrically. An international team of researchers used beamline I06 to investigate a ferromagnetic film of nickel when it served as a sensitive strain gauge for single-crystal PMN-PT. Their initial interpretation of the results suggested that ferroelectric domain switching rotated the magnetic domains in the film by the expected angle of 90°, but a closer examination revealed the true picture to be more complex. Their work, recently published in Nature Materials, shows that the ferroelectric domain switching rotated the magnetic domains in the film by considerably less than 90° due to an accompanying shear strain. The findings offer both a challenge and an opportunity for the design of next-generation data storage devices, and will surely be relevant if the work is extended to explore the electrically driven manipulation of more complex magnetic textures.

>Read more on the Diamond Light Source website

Image: Magnetic vector map (50 µm field of view) describing the magnetisation of a Ni film while applying 50 V across the ferroelectric substrate of PMN-PT. The colour wheel identifies magnetisation direction. Yellow and brown denotes regions whose magnetisation was unaffected by the voltage.

Study offers new target for antibiotic resistant bacteria

As antibiotic resistance rises, the search for new antibiotic strategies has become imperative. In 2013, the Centers for Disease Control estimated that antibiotic resistant bacteria cause at least 2 million infections and 23,000 deaths a year in the U.S.; a recent report raised the likely mortality rate to 162,044.
New Cornell research on an enzyme in bacteria essential to making DNA offers a new pathway for targeting pathogens. In “Convergent Allostery in Ribonucleotide Reductase,” published June 14 in Nature Communications, researchers used the MacCHESS research stations at the Cornell High Energy Synchrotron Source (CHESS) to reveal an unexpected mechanism of activation and inactivation in the protein ribonucleotide reductase (RNR).

Understanding the “switch” that turns RNR off provides a possible means to shut off the reproduction of harmful bacteria.
RNRs take ribonucleotides, the building blocks of RNA, and convert them to deoxyribonucleotides, the building blocks of DNA. In all organisms, the regulation of RNRs involves complex mechanisms, and for good reason: These mechanisms prevent errors and dangerous mutations.

>Read more on the CHESS website

Image: William Thomas, a graduate student in the field of chemistry and chemical biology, collects data on ribonucleotide reductase.