MAX IV – Page 2 – Lightsources.org

Unusual electronic properties taking shape

2021/06/132021/06/29

In a recent study, an international team led by researchers from The Pennsylvania State University in the US investigated the one-dimensional (1D) material tantalum selenide iodide (TaSe₄ )₂I. Its electronic properties had been theoretically predicted but not observed experimentally before the study conducted at the Bloch beamline. Evaporating iodine atoms turn out to drive unforeseen electronic changes.

Materials with unusual electronic properties such as charge density waves or topological states push the understanding of the fundamentals of quantum matter. They are also exciting candidates for the next generations of energy-efficient electronic and spintronic devices.

In the present study, the researchers found that the electronic properties of (TaSe₄ )₂I were different from the theoretical prediction. The band structure of a material can loosely be compared to a map of the material’s electronic properties. (TaSe₄ )₂I has something called Dirac bands, which is often found in this type of materials. The prediction said that the Dirac bands would split due to Weyl physics, which is not the case. The bands split with temperature, and the driver behind it is iodine atoms evaporating from the material’s surface.

Read more on the MAX IV website

Image: Surface charge induced Dirac band splitting in 1D material (TaSe₄ )₂I

Riverine iron survives salty exit to sea

2021/04/012021/04/08

Iron organic complexes in Sweden’s boreal rivers significantly contribute to increased iron concentration in open marine waters, X-ray spectroscopy data shows. A Lund University study in Biogeosciences characterizes the role of salinity for iron-loading in estuarine zones, a factor which underpins intensifying seasonal algal blooms in the Baltic Sea.

The study ties in with a reported trend of increased riverine iron concentrations over the last decade in North America, northern Europe and in particular, Swedish and Finnish rivers. This, in conjunction with a predicted rise in extreme weather events in Scandinavia due to climate change, provides momentum for more bioavailable iron to enter marine environments such as the Baltic Sea.

“The consequences of increasing riverine iron for the receiving [marine] system depend first and foremost on the fate of iron in the estuarine salinity gradient. We had questions on what factors determine the movement and transport capacity of iron in these boreal rivers,” said Simon Herzog, postdoctoral researcher at Lund University.

The research group investigated the iron discharge in eight boreal rivers in Sweden which drain into the Baltic Sea, a brackish marine system. Water samples were taken upstream and at the river mouths, the latter just before estuarine mixing and stronger saline conditions occur. Spring and autumn specimens enabled the comparative analysis of flow conditions. To determine the type and amounts of iron species, measurements with X-ray absorbance spectroscopy (XAS) were taken at beamline I811 at Max-lab in Lund, Sweden and X-ray Absorption Near-Edge Structure (XANES) spectra at beamline ID26 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.

Read more on the MAX IV website

Image: A view of the Ore River in northern Sweden

Credit: Simon Herzog

Focused X-ray beam allows high-resolution nanowire strain mapping

2020/09/302020/10/01

A team of researchers from Lund University and Northwestern University in the United States have used the nano focused beam at the NanoMAX beamline to construct a 2D map of the distribution of material strain in individual InP-GaInP heterostructure nanowires. Understanding the strain that forms in heterostructure nanowires is essential for tailoring their electronic properties to applications in electronics and for energy materials.

Semiconductor materials are essential for everything from electronics such as computers and mobile phones to LED-lights and solar cells. Different types of semiconductor materials often need to be combined in a so-called heterostructure to realise the advanced functions required for these devices.

Typically the combination is done by growing layers of one semiconductor material on top of another. However, since the distances between the atoms, the lattice spacing, is different in the different materials, it often leads to mismatch and strain in the materials when they are combined in this way. The mismatch puts a limit on what materials are possible to mix and how thick the layers can be.

ARIEs as key resources for the five Horizon Europe Missions

2020/07/282020/07/28

Moon-shot missions, such as those of Horizon Europe, require exceptional solutions, and the world-leading Analytical Research Infrastructures of Europe (ARIEs) are one of the key places those solutions can be sought. The ARIE Joint Position Paper highlighting how the common, complementary approach will help address the societal challenges of the Horizon Europe Missions framework programme was presented today.

“The Analytical Research Infrastructures of Europe (ARIEs) provide unique windows into the workings of the world around us”, says Caterina Biscari, Chair of LEAPS and Director of the ALBA Synchrotron in Spain. “The cross-border cooperation within Europe allows for harnessing the power of its analytical research infrastructures collectively, to fuel the cutting-edge R&D required by the five Horizon Europe Missions. Nowhere else in the world is this readily possible.”

The ARIEs are centres of scientific and technological excellence, delivering services, data and know-how to a growing and diverse user community of more than 40,000 researchers in academia and industry, across a range of domains: the physical sciences, energy, engineering, the environment and the earth sciences, as well as medicine, health, food and cultural heritage. They include powerful photon sources, such as synchrotrons, laser systems and free-electron lasers; sources of neutrons, ions and other particle beams; and facilities dedicated to advanced electron-microscopy and high magnetic fields.

Read more on the MAX IV website

X-ray beams help seeing inside future nanoscale electronics

2020/07/222020/08/03

The technological advancement of fourth-generation synchrotrons, pioneered by MAX IV Laboratory, opens research opportunities that were impossible just a few years ago. In a newly published research paper, we get proof of the revolutionary impact that MAX IV’s photons can have for the advancement of nanoelectronics, both in research and for industrial manufacturers.

Thanks to the innovative concept of the multi-band achromats, MAX IV Laboratory has paved the way for fourth-generation synchrotrons and as of now, it is the most brilliant source of X-ray for research. The high coherence and brilliance delivered at MAX IV are giving scientists the tools for performing research previously unachievable in the X-ray spectrum. This potential is highlighted in a new publication centred on investigating innovative non-destructive characterization of embedded nanostructures.

Read more on the MAX IV website

Image: Depiction of the process of nanofocused X-ray beams scattering from a single nanowire transistor. Positively charged particles (+) and negatively charged particles (-) represent charge carriers in a p–n junction (where p–n junction is an interface between p-type and n-type semiconductor materials). Outgoing beams, depicted as white rays, represent scattering from different segments of the device (InAs and GaSb). The bending with arrows represents the strain revealed in the experiment.

Credit: Illustration by Dmitry Dzhigaev, Lund University.

Atomic vibrations play key role in material phase change

2020/06/092020/06/10

A research group working with MAX IV’s FemtoMAX beamline has succeeded to slow the phase change from the solid to liquid state in the semiconductor, indium antimonide (InSb), by reducing the inherent vibrations between atoms. An important precursory step in the process was non-thermal melting of the sample, which broke its atomic bonds. This revealed that unbound atoms move with the velocity they had at the instant the bonds were broken. Further it showed that initial velocity is governed by atomic vibrations, which in turn are temperature dependent. The findings are steps toward functional manipulation of material structure during phase transitions.

Imagine a world where we control the structure of materials by subjecting them to short-pulse laser radiation. This is the implication of research that allows us to alter the timing when phase change occurs.

Melting a material with or without heat produces a similar result, at a similar speed. What is going on at the atomic level is quite different, however. Thermal heating excites electrons to a higher energy state. Electron-phonon coupling then equilibrates the electron and lattice temperature which makes the lattice vibrate so violently that atomic bonds break. Non-thermal heating also excites electrons but breaks the bonds instantly—within femtoseconds—and releases atoms from their original structural configuration. Scientists seek to distinguish what happens after bonds sever due to these excited electrons.

Read more on the MAX IV website

Image : FemtoMAX beamline at MAX IV

An innovative mirror unit for soft X-ray beamlines at MAX IV

2020/05/202020/05/21

A new five-axis parallel kinematic mirror unit has been developed for MAX IV soft X-ray beamlines. Its development and technical characteristics are now described in a peer-reviewed article.

In an article published in March 2020 in the Journal of Synchrotron Radiation, a team from Uppsala University, MAX IV Laboratory, FMB Feinwerk und Messtechnik GmbH, and University of Tartu presents a five-axis parallel kinematic mirror unit specially developed for MAX IV soft X-ray beamlines. This new mirror unit has been created to address the unique stability requirements of 4th-generation synchrotrons such as MAX IV.

MAX IV has pioneered the development of the 4th-generation synchrotrons thanks to the implementation of the multi-bend achromat technology, a system based on the use of several sequential bending magnets in place of a single large magnet. Thanks to the introduction of this technology, the emittance has decreased by one order of magnitude, resulting in increased brightness. The multi-bend achromat system has also brought new challenges for the construction of beamlines. Decreased emittance of the storage ring has allowed for a smaller beam size, which, in turn, means higher requirements for electron beam stability, as well as for mechanical stability of the beamline components.

>Read more on the MAX IV website

Image: Veritas is one of the beamlines at MAX IV used for testing the prototype of the new five-axis parallel kinematic mirror.

A revolutionary setup for atomic layer deposition at SPECIES

2020/04/152020/04/15

In a joint project across three universities and MAX IV laboratory, researchers have developed a revolutionary experimental setup for atomic layer deposition.

The new instrument was designed specifically for MAX IV and will allow for observations previously impossible.
SPECIES, one of the soft X-ray beamlines in MAX IV 1.5 GeV storage ring, has added to its portfolio a new cutting-edge instrument. The new experimental setup has been specially developed to use Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS) for the study of atomic layer deposition (ALD), a process where thin films of material are grown depositing one layer at a time.

This experimental setup is composed of a custom cell where the ALD process is performed and observed using APXPS. The instrument is the result of an extensive collaboration between the University of Helsinki, world-leading in ALD studies, University of Oulu, Lund University, and MAX IV Laboratory, and funded by the University of Helsinki through the FiMAX consortium.
In February, the team from the University of Helsinki led by professor Mikko Ritala, and from the University of Oulu came to MAX IV for the final experiments and refinement activities on the experimental setup. We talked with the scientists to understand how the cell they have developed allows for unprecedented observations.

>Read more on the MAX IV website

Image credit: Matti Putkonen.

Beyond graphene: monolayer arsenene observed for the first time

2020/02/272020/02/27

An article recently published in 2D Materials shows the first experimental evidence of the successful formation of arsenene, an analogue of graphene with noteworthy semiconducting properties.

This material shows a great potential for the development of new nanoelectronics. Crucial sample preparation and electron spectroscopy experiments were performed at the Bloch beamline at MAX IV.

The discovery of graphene, the single-layer carbon honeycomb material worth the Nobel Prize in Physics in 2010, surely has had a revolutionary impact on research. It triggered a whole new field of study within two-dimensional (2D) materials. However, its application in developing new 2D electronics has been hindered by its lack on an intrinsic band gap. Researchers therefore started to turn their attention to other elements in the periodic table and set their eyes on group V, to which arsenic belongs.
“The aim of the study was to show that arsenene can be formed. Our article is the first to report this”, says Roger Uhrberg, professor at Linköping University and spokesperson for the Bloch beamline at MAX IV. Arsenene, a single-layer buckled honeycomb structure of arsenic, had been previously predicted by various theoretical studies, but this is the first experimental observation that verifies its existence.

>Read more on the MAX IV website

Image: A view of the Bloch beamline at MAX IV. The Bloch beamline consists of two branchlines, and is dedicated to high resolution photoelectron spectroscopy, encompassing angle-resolved (ARPES), spin resolved (spin-ARPES) and core-level spectroscopy.

The role of synthesis gas in tomorrow’s sustainable fuels

2020/02/062020/02/24

In a new publication in Nature Communications, a team from the Dutch company Syngaschem BV and the Dutch Institute for Fundamental Energy Research elucidates for the first time some aspects of the Fischer-Tropsch reaction, used for converting synthesis gas into synthetic fuels.

Analysis performed at HIPPIE beamline at MAX IV were instrumental to achieve these results. The adoption of sustainable and renewable energy sources to permanently move beyond the dependence from fossil fuels constitutes one of the great challenges of our time. One that is made more urgent by the effects of climate change we witness on a daily basis. Electrification, such as we see in the development of electric vehicles, seems a promising strategy, but it cannot be the solution for all applications. In many cases liquid fuels are still considered the best and most efficient option. Is there a way to produce liquid fuels in an efficient and sustainable manner, one that does not rely on fossil sources?

>Read more on the MAX IV website

Discovering a whole new family of copper-binding proteins

2020/01/162020/01/23

While studying a class of copper-containing enzymes, a team of researchers discovered and characterised a new family of fungal proteins.

Their study has now been published on Nature Chemical Biology, including analysis performed at BioMAX. The article is published together with a parallel study that sheds light on one of the potential biological roles of the proteins in this new family.

In contrast with a certain romanticised idea of research, scientific discoveries seldom come with a shouted “eureka!” as to mark the end of a linear intellectual endeavour. Much more frequently, new scientific findings emerge from observations where a scientist’s first reaction might sound like “that’s odd…”. Perhaps that was how the authors of this study reacted when they realised what they were looking at wasn’t what they were looking for.

In an article published this week on Nature Chemical Biology, a team of scientists from INRA, University of Copenhagen, Marseille Université, and University of York characterised a new family of proteins, named X325, found in various fungal lineages. The article is published together with a parallel study in which one protein of this new family, Bim1, is described as involved in fungal meningitis.

The authors were initially searching for new lytic polysaccharide monooxygenases (LPMOs), copper-dependent enzymes specialised in the degradation of polysaccharides and widely used in the production of biofuels. The proteins of this new family seemed promising candidates since they share many structural features and a probable common ancestor with LPMOs. However, the researchers proved that the members of this LPMO-like protein family are not involved in polysaccharides degradation, but they more likely play a role in the regulation of copper ion content in the organisms where they are expressed.

>Read more on the MAX IV website

Image: Copper binding site of two different proteins. Left: LaX325 protein belonging to the newly identified LPMO-like protein family X325. Right: cellulose cleaving LPMO enzyme TaAA9.
Image developed by Tobias Tandrup, University of Copenhagen.

First delivery of single-bunch electron beam to the 1.5 GeV ring

2019/10/222019/10/24

The 22 October at lunchtime, the first single-bunch electron beam was delivered to the 1.5 GeV storage ring at MAX IV and put to use at the FinEstBeAMS beamline.

These are still preliminary trials and the response from FinEstBeAMS will determine the path forward.

Normally the electrons in the storage rings come in so-called multi-bunch formation. You could think of this as several locomotives with many wagons travelling around the ring. In single-bunch mode, there is only one locomotive “on the track”. The abstract of Christian Strålman’s PhD thesis On the Challenges for Time-of-Flight Electron Spectroscopy at Storage Rings gives a good overview of the topic in Swedish.

The single-bunch mode will give the scientists access to a wider portfolio of measurement techniques in several research areas such as atmospheric chemistry, environmental science (in particular renewable energy sources), molecular reaction dynamics, cluster chemistry and physics, materials science, chemistry–chemical reactions at surfaces or in solution and photocatalysis.

>Read more on the MAX IV website

Image (extract):A screenshot of a scope measurement of the current in the ring, where you can clearly see the strong single-bunch signal. See full image here.

Discoveries map out CRISPR-Cas defence systems in bacteria

2019/09/252019/09/27

For the first time, researchers at the University of Copenhagen have mapped how bacterial cells trigger their defence against outside attacks. This could affect how diseases are fought in the future.

With the aid of highly advanced microscopes and synchrotron sources, researchers from the University of Copenhagen have gained critical insight into how bacteria function as defence mechanisms against attacks from other bacteria and viruses. The study, which has just been published in the renowned journal, Nature Communications, also describes how the defence systems can be activated on cue. This discovery can turn out to be an important cornerstone in fighting diseases in the future.

The researchers have shown how a cell attacked by a virus activates a molecule called COA (Cyclic Oligoadenylate), which in turn activates a so-called protein complex called CSX1 to eradicate the attacker.

>Read more on the MAX IV website

Image: Model of the CSX1 protein complex.

New research possibilities at NanoMAX

2019/09/062019/09/12

X-rays can penetrate materials and are therefore useful for studying chemical processes as they occur inside reactors, cells, and batteries. A common ingredient in such chemical systems is metal nanoparticles, which are often used as catalysts for important reactions. As the NanoMAX beamline provides a very small X-ray focal spot, single nanoparticles can in principle be studied as they perform their catalytic functions.

In this paper, we show that gold nanoparticles sitting inside an electrochemical cell can be imaged at NanoMAX. These preliminary results come from nanoparticles around 60 nm (60 millionths of a millimetre) in size, and we show that even smaller particles could be studied. If successful, future experiments will allow “filming” nanoparticles as they catalyze reactions in real-time, and give new understanding of how catalysis works. That could in turn help design new materials for energy conversion, chemical production, and water purification.

>Read more on the MAX IV Laboratory
Image (extract, full image here): Coherent Bragg imaging of 60 nm Au nanoparticles under electrochemical control at the NanoMAX beamline

Collaboration develops sensitive data protocol

2019/08/162019/08/22

MAX IV pairs up with Sprint Bioscience, a listed drug development company, in a new project to improve how companies can benefit from new, faster X-ray fragment screening experiments, while still protecting their valuable information during analysis at FragMAX.

Recently, the project was granted with 500 000 SEK from Sweden’s innovation agency Vinnova.
More or less, all pharmaceutical drugs are molecules binding to proteins in your body. When doing this, they either initiate or inhibit the process in which the target protein is involved. Proteins are in charge of everything from cells dividing at the right moment to the metabolism of the food you eat or signaling in the brain.

>Read more on the MAX IV website

Image: Sample holders
Credit: Ben Libberton

17 meter long detector chamber delivered to CoSAXS

2019/05/142019/05/15

The experimental techniques used at the CoSAXS beamline will use a huge vacuum vessel with possibilities to accommodate two in-vacuum detectors in the SAXS/WAXS geometry.

A major milestone was reached for the CoSAXS project when this vessel was recently delivered, installed and tested.
The main method that will be used at the CoSAXS beamline is called Small Angle X-ray Scattering (SAXS). By detecting the scattered rays coming from the sample at shallow angles, less than 4° typically, it is possible to learn about the size, shape, and orientation of the small building blocks that make up different samples and how this structure gives these materials their properties. The materials to be studied can come from various sources and in diverse states, for example, plastics from packaging, food and how it is processed or proteins in solution which can be used as drugs.
The “co” in CoSAXS stands for coherence, a quality of the synchrotron light optimized at the MAX IV machine, that loosely could be translated as laser-likeness. In the specific case of X-ray Photon Correlation Spectroscopy (XPCS), it lets the researchers not only measure the structure of the building blocks in the sample but also their dynamics – how they change in time.