Rigid bonds enable new data storage technology
How new phase-change materials could lead to more efficient and faster data storage technologies
Peter Zalden, European XFEL
Phase-change materials made of compositions of the elements antimony, tellurium and germanium, can be used to store increasingly large amounts of data, and do so quickly and energy efficiently. They are used, for example, in replacements for flash drives in the latest generation of smartphones. When an electrical or optical pulse is applied to heat these materials locally, they change from a glassy to a crystalline state, and vice versa. These two different states represent the ‘0’ and ‘1’ of the binary code needed to store information. However, to date it has not been possible to resolve how exactly these changes of state occur on an atomic level.
In an experiment at the Linac Coherent Light Source (LCLS) in California, a group of scientists led by researchers from European XFEL and the University of Duisburg-Essen used a technique called femtosecond X-ray diffraction to study atomic changes when the materials switch state. In the experiment, that took place before European XFEL was operational, an optical laser was first used to trigger the material to change between crystalline and glassy states. During this extremely fast process, the X-ray laser was used to take images of the atomic structure. Only X-ray Free-Electron Lasers such as LCLS or European XFEL produce X-ray pulses that are short and intense enough to capture snapshots of the atomic changes occurring on such short timeframes. The scientists collected over 10,000 images in order to shed light on the sequence of atomic changes that occur during the process.
To store information with phase-change materials, they must be cooled quickly to enter a glassy state without crystallizing. They must also stay in this glassy state for as long as the data is to be stored. This means that the crystallization process must be very slow to the point of being almost absent, such as is the case in ordinary glass. At high temperatures, however, the same material must be able to crystallize very quickly to erase the information. The way a material can form a stable glass but at the same time becomes very unstable at elevated temperatures has puzzled researchers for decades.
In their experiment, the researchers studied the fast cooling process, by which a glass is formed. They found that when the liquid is cooled sufficiently far below the melting temperature, it undergoes a structural change to form another, low-temperature liquid. This low-temperature liquid can only be observed on very short timescales, before crystallization takes place. The two different liquids had not only very different atomic structures, but also different behaviors: The liquid at high temperature has a high atomic mobility that enables the atoms to crystallize, i.e., to arrange in a well-ordered structure. However, when the liquid passes below a certain temperature below the melting point, some chemical bonds become stronger and more rigid and can hold the disordered atomic structure of the glass in place. These observations were supported by computer simulations performed at RWTH Aachen University. The simulations provided further details of the atomic structure of the two liquids and revealed changes in the electronic properties, showing that the high-temperature liquid is more metallic than the low-temperature liquid – consistent with the formation of more rigid bonds. It is only the rigid nature of these chemical bonds that prevents the transformation and – in the case of phase-change memory devices – secures the information in place.
Peter Zalden, scientist at European XFEL and first author of the study explains “current data storage technology has reached a scaling limit so that new concepts are required to store the amounts of data that we will produce in the future. Our study explains how the switching process in a promising new technology based on glass formation can be fast and reliable at the same time.”
Klaus Sokolowski-Tinten from the University of Duisburg-Essen, who initiated the project, adds “the results and our time-domain approach can also help to understand how liquids of other classes of materials behave when they are rapidly cooled to temperatures well below the melting point and form a glass. This year we will do similar experiments at different facilities worldwide – including the European XFEL – where the femtosecond pulses are short and intense enough to capture snapshots of these fast processes.”
Other news from the department science
Blue-green algae sugar instead of glyphosate
Cooperation project develops environmentally friendly glyphosate alternative
Using clay to combat eternal toxins
TU Freiberg clarifies basis for innovative PFAS filter made of clay
Unveiling a new era of imaging: Boston University engineers lead breakthrough microscopy techniques
Researchers made significant advancements in the field of vibrational imaging
Phasing out fossil fuels could save millions of lives
The mortality burden attributable to air pollution from fossil fuel use is considerably higher than most previous estimates - a phaseout of fossil fuels would have tremendous, positive health outcomes
Replicating the structure of bird feathers
The new material could be used in batteries or filtration
Quantum tool opens door to uncharted phenomena
Method can contribute to a better understanding of quantum materials
Recovering instead of shredding: recycling batteries more efficiently
KIT researchers are working with industry to develop a more sustainable recycling process to recycle materials from lithium-ion batteries more effectively
Industry 4.0: No impact on energy consumption?
To what extent does the digitalisation of industrial and manufacturing processes (Industry 4.0) improve energy efficiency and thus reduce energy intensity?
New approach to the sensible utilisation of carbon dioxide from car exhaust gases
"A method has been discovered that uses impure CO2 streams and enables a breakthrough in the synthesis of valuable chemicals and pharmaceuticals"
Boosting PET recycling with higher standards for laboratory experiments
New study shows how enzymatic plastic degradation could be brought one step closer to commercialisation
Innovating Optoelectronic Components with Phosphorus
Significant breakthrough: phosphorus chemists develop new method to selectively introduce phosphorus and nitrogen atoms into polyaromatic systems
Artificial intelligence finds ways to develop new drugs
The chemists tested the process using borylation – a reaction that activates hydrocarbon scaffolds
X-rays reveal how glasses lose their stability
PETRA III experiment shows how atoms in glass behave as weaknesses appear
Most read news
Plastic-eating bacteria turn waste into useful starting materials for other products
Microbial Upcycling of Waste PET
Microbes could help reduce the need for chemical fertilizers
A coating protects nitrogen-fixing bacteria: Start-up to commercialise coated bacteria for large-scale use in regenerative agriculture
New designs for solid-state electrolytes may soon revolutionize the battery industry
Scientists achieve monumental improvements in lithium-metal-chloride solid-state electrolytes
Inauguration of the world’s first pilot plant for the cost-efficient production of green methanol
Start-up C1 Green Chemicals AG and research partners develop fundamentally new production process
Dow and Evonik announce startup of hydrogen peroxide to propylene glycol (HPPG) pilot plant
Innovative technology offer flexibility, lower costs, and a smaller environmental footprint
This is a battery
Two colored liquids bubbling through tubes: Is this what the battery of the future looks like?
Converting PFAS “forever chemicals” into valuable compounds
Scientists develop a new method to incorporate harmful perfluoroalkenes into N-heterocyclic carbene ligands
Not so silver lining: Microplastics found in clouds could affect the weather
Low-altitude and denser clouds contained greater amounts of microplastics
Graphene's proton permeability: A switch for future energy technologies
This discovery could lead to the development of more efficient hydrogen fuel cells and solar water-splitting devices
Lithium-ion batteries are no longer the gold standard in battery tech
On the way to safer and more powerful energy sources
CO2-free hydrogen: BASF receives funding approval for 54-megawatt water electrolysis plant
Proton exchange membrane (PEM) electrolyzer expected to produce up to 8,000 metric tons of hydrogen per year
More news from our other portals
Bowel cancer: aspirin activates protective genes
Researchers have identified a signaling pathway by which aspirin can inhibit colorectal cancer.
Dunning-Kruger effect with muesli bars
Those who know the least consider themselves highly competent
Autonomous measuring instruments systematically detect new materials
A new algorithm measures materials libraries up to four times faster than before: It’s based on machine learning
New drug delivery system could reduce daily diabetes shots to just three a year
Dietary management drugs have transformed Type 2 diabetes care, but daily injection routines are challenging for some patients
Naked Clams: The New Superfood Sensation Emerging from the Depths
Researchers found Naked Clams contain almost twice the amount of Vitamin B12 as blue mussels and have developed an efficient way to farm them
Researchers discover new ultra strong material for microchip sensors
A material that doesn't just rival the strength of diamonds and graphene, but boasts a yield strength 10 times greater than Kevlar
Aston University technology to combat the not-so sweet practice of honey fraud
Light technology to be used to detect if honey is blended with cheap additions
How stem cells and immune cells communicate
Lisec Artz Award for Simon Haas: Groundbreaking discovery of an unknown protective mechanism against blood cancer from stem cells
Pushers, overcrowded trains and phone zombies
Sprite presents the world's first vending machine that responds to the things that bother Generation Z the most
Scientists use quantum biology, AI to sharpen genome editing tool
"This study represents an exciting advancement toward, understanding how we can avoid making costly ‘typos’ in an organism’s genetic code"
Tönnies Group launches first nationwide "Meat Climate Platform"
100 guests at the Future Forum for Agriculture
Viral Impostors: Breakthrough for Virus Research
The penetration of viruses into cells can now be tracked with unprecedented accuracy thanks to innovative design for pseudoviruses
From the trough to the plate - digitally calculated
Computer program "ConTrans" estimates how much of an undesirable substance is transferred from animal feed to food
Fatty acid factory filmed at work
High-resolution images provide new insights into cellular fatty acid production: Potential for medicine and biotechnology
Tracking down Environmental Toxins
Detection of per- and polyfluoroalkyl substances (PFAS) by interrupted energy transfer
Textbook knowledge turned on its head: 3-in-1 microorganism discovered
Newly multifunctional bacterial species
Are healthy foods automatically sustainable, too?
Perceptions about sustainability and healthy food choices are closely linked
The weight of pollution: exposure linked to obesity
Chronic exposure to environmental pollutants found to increase risk of cardiovascular disease
Could eating turkey ease colitis?
According to data in mice, extra tryptophan could reduce the risk of future colitis flares