(Press-News.org) While searching for ever smaller devices that can be used as data storage systems and novel sensors, physicists at Johannes Gutenberg University Mainz (JGU) have directly observed magnetization dynamics processes in magnetic nanowires and thus paved the way for further research in the field of nanomagnetism. Small magnetic domain wall structures in nanowires can be used to store information and, for example, can be used as angle sensors. Initial applications based on magnetic domain walls have been developed and are already in use in sensor technology. The current findings represent the first experimentally recorded direct imaging of predicted correlations between magnetic spin structure and wall velocity. The newly discovered properties could be used for other future applications in information technology.
Magnetic domains represent regions of uniform magnetization in ferromagnetic materials. Within each domain, the magnetization is aligned in a single direction. At the interface where domains of different magnetization direction meet, the magnetization has to rotate from one direction to another in a so-called domain wall. At Mainz University, the group of Professor Mathias Kläui is studying the properties of magnetic domains and the dynamics of domains and domain walls in tiny rings on the nanoscale. It is possible to directly observe the motion of domain walls in these rings that have a diameter of some 4 micrometers and are made of permalloy, a soft nickel-iron alloy. For this purpose, the Mainz physicists have been collaborating with scientists of the BESSY II synchrotron facility at the Helmholtz Center Berlin for Materials and Energy and the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory, Berkeley, USA, as well as with the Technical University of Berlin and the Max Planck Institute for Intelligent Systems in Stuttgart.
The researchers discovered that the velocity of the motion of domain walls is always oscillating. "This is a new effect that could prove to be useful in the future," said Dr. André Bisig, lead author of the paper "Correlation between spin structure oscillations and domain wall velocities," which has recently been published in Nature Communications. It was also found that the applied method is very effective in reliably moving the domain walls at very high velocities. "The faster we move the domain wall, the easier it is to control it," said Bisig. Another observation concerns the effects associated with irregularities or defects in the nanowires. According to the results, these effects only become noticeable when domain walls are moving slowly. The faster a domain wall spins, the less relevant is the role played by defects in the material.
While theoretical research concerns itself principally with observing domain wall velocity and its correlation with oscillations in the spin structure, the results obtained also have important implications for applied research. Domain wall-based sensors are already being used by Sensitec GmbH, Mainz, a cooperating partner of JGU and the Technical University of Kaiserslautern in two projects funded by the state of Rhineland-Palatinate: the Spintronics Technology Platform in Rhineland-Palatinate (STeP) and the Technology Transfer Service Center for New Materials (TT-DINEMA). "Of particular importance is the fact that we observed unimpeded domain wall motion at high domain wall velocities. This represents highly promising potential for the use of these nanostructures in ultra-fast rotating sensors," added Professor Mathias Kläui. The research being undertaken by Professor Kläui's team is being funded by an ERC Starting Grant and the Graduate School of Excellence Materials Science in Mainz (MAINZ). In addition, cooperation with Sensitec has resulted in access to a joint EU project involving seven other leading partners expected to start in October 2013 on "Controlling domain wall dynamics for functional devices".
INFORMATION:
Image:
http://www.uni-mainz.de/bilder_presse/08_physik_komet_domaenenwaende.jpg
Image of a ferromagnetic ring prepared using a scanning electron microscope: The magnetization (black/white contrast) runs along the ring and forms two domain walls.
source: © André Bisig, Institute of Physics, Johannes Gutenberg University Mainz
Publication:
André Bisig et al.
Correlation between spin structure oscillations and domain wall velocities
Nature Communications, 27 August 2013
DOI: 10.1038/ncomms3328
http://www.nature.com/ncomms/2013/130827/ncomms3328/full/ncomms3328.html
Further information:
Dr. André Bisig
Kläui Lab
Condensed Matter Theory
Institute of Physics
Johannes Gutenberg University Mainz (JGU)
D 55099 Mainz, GERMANY
phone +49 6131 39-23635
e-mail: bisig@uni-mainz.de
http://www.klaeui-lab.physik.uni-mainz.de/
Domain walls as new information storage medium
Visualization of domain wall motion: Material defects do not impede wall motion at high velocities / Publication of findings in Nature Communications
2013-09-23
ELSE PRESS RELEASES FROM THIS DATE:
First steps towards achieving better and cheaper biodiesel
2013-09-23
This news release is available in Spanish. Is there any connection between wine and biodiesel? The answer is yes, however surprising it may seem. Acetals are chemical compounds found in many wines, like port, for example, which give it a unique, sweet smell. However if acetals are blended with biodiesel, they improve its properties. The SUPREN research group of the Department of Chemical Engineering and the Environment of the Faculty of Engineering in Bilbao (UPV/EHU) is working on a project that is seeking to encourage the use of this rare fuel. The idea is to produce ...
Researchers probe the optical properties of a novel kind of magnetism
2013-09-23
CAMBRIDGE, Mass-- Using low-frequency laser pulses, a team of researchers has carried out the first measurements that reveal the detailed characteristics of a unique kind of magnetism found in a mineral called herbertsmithite.
In this material, the magnetic elements constantly fluctuate, leading to an exotic state of fluid magnetism called a "quantum spin liquid." This is in contrast to conventional magnetism, found in materials called ferromagnets — where all of the magnetic forces align in the same direction, reinforcing each other — or antiferromagnets, where adjacent ...
Eagle vs. deer
2013-09-23
NEW YORK (September 18, 2013) — A camera trap set out for endangered Siberian (Amur) tigers in the Russian Far East photographed something far more rare: a golden eagle capturing a young sika deer.
The three images only cover a two-second period, but show an adult golden eagle clinging to the deer's back. Its carcass was found two weeks later, just a few yards from the camera, initially puzzling researchers.
The paper and images appear in the September issue of the Journal of Raptor Research. Authors include Linda Kerley of the Zoological Society of London (ZSL) and ...
How 'bad' cholesterol causes atherosclerosis in humans: Stem cells play a key role
2013-09-23
BUFFALO, N. Y. -- University at Buffalo translational researchers are developing a richer understanding of atherosclerosis in humans, revealing a key role for stem cells that promote inflammation.
The research was published last month in PLOS One. It extends to humans previous findings in lab animals by researchers at Columbia University that revealed that high levels of LDL ("bad") cholesterol promote atherosclerosis by stimulating production of hematopoietic stem/progenitor cells (HSPC's).
"Our research opens up a potential new approach to preventing heart attack and ...
Protein explains increased asthma severity in children exposed to diesel exhaust from traffic
2013-09-23
A new study shows that exposure to diesel exhaust particles from traffic pollution leads to increased asthma severity in children. Moreover, the study finds that this is due to increased blood levels of IL-17A, a protein associated with several chronic inflammatory diseases, in children with high diesel exposure.
The study by researchers at Cincinnati Children's Hospital Medical Center is published online in the Journal of Allergy and Clinical Immunology.
The research, conducted in mice and in humans, showed that neutralizing IL-17A prevented airway inflammation. Neutralization ...
Rising rates of severe and fatal sepsis during labor and delivery
2013-09-23
San Francisco, CA. (September 23, 2013) – Rates of severe sepsis and deaths from sepsis among U.S. women hospitalized for delivery have risen sharply over the last decade, reports a study in the October issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).
"Maternal severe sepsis and sepsis-related deaths are increasing in the United States," concludes the report by Dr Melissa E. Bauer of University of Michigan Health System, Ann Arbor, and colleagues. Although the study identifies certain groups of women at increased ...
The fish and the egg: Towards a new strategy for fattening up red drum in Texas
2013-09-23
It's not the chicken or the egg, but marine scientists at The University of Texas at Austin have answered a basic question about red drum fish and their eggs that may eventually help save the state of Texas a great deal of money in hatcheries management and make fish farming more environmentally friendly.
Every year the Texas Parks & Wildlife Department spends millions of dollars breeding red drum, a popular game fish, releasing between 20 and 30 million hatchery-raised fingerlings into eight different bays and estuaries along the coast. In order to maximize the numbers ...
Public says childhood cancer should be top children's health research priority
2013-09-23
ANN ARBOR, Mich. – Adults across the U.S. rate childhood cancer as their top priority for research into improving children's health, according to a new University of Michigan C.S. Mott Children's Hospital National Poll on Children's Health.
September is National Childhood Cancer Awareness month, and in this latest poll, 76 percent of adults rated research into childhood cancers as "very important." That was followed by diabetes, with 70 percent rating it "very important" and birth defects or other genetic problems with 68 percent.
"So many people know a child or family ...
It takes a(n academic) village to determine an enzyme's function
2013-09-23
CHAMPAIGN, Ill. — Scientists have sequenced the genomes of nearly 6,900 organisms, but they know the functions of only about half of the protein-coding genes thus far discovered. Now a multidisciplinary effort involving 15 scientists from three institutions has begun chipping away at this mystery – in a big way. Their work to identify the function of one bacterial protein and the biochemical pathway in which it operates will also help identify the functions of hundreds of other proteins.
A report of their new approach and findings appears in the journal Nature.
The ...
Putting the spring back in broken hearts
2013-09-23
The threat from a heart attack doesn't end with the event itself. Blockage of blood flow to the heart can cause irreversible cell death and scarring. With transplants scarce, half the people who live through a heart attack die within five years. Scientists are trying to address this problem by engineering cardiac tissue to patch up damaged areas.
Now doctoral students Sharon Fleischer and Ron Feiner — under the supervision of Dr. Tal Dvir of Tel Aviv University's Department of Molecular Microbiology and Biotechnology and the Center for Nanoscience and Nanotechnology — ...
LAST 30 PRESS RELEASES:
McGill discovery sheds new light on autism, intellectual disabilities
Cellular changes occur even below the hexavalent chromium limit
Study suggests a new way to curb social media’s body image toll
Plant doctor: An AI system that watches over urban trees without touching a leaf
Study tracks chromium chemistry in irradiated molten salts
Scientists: the beautiful game is a silver bullet for global health
Being physically active, even just a couple of days a week, may be key to better health
High-fat diet promote breast cancer metastasis in animal models
A router for photons
Nurses and AI collaborate to save lives, reduce hospital stays
Multi-resistance in bacteria predicted by AI model
Tinker Tots: A citizen science project to explore ethical dilemmas in embryo selection
Sensing sickness
Cost to build multifamily housing in California more than twice as high as in Texas
Program takes aim at drinking, unsafe sex, and sexual assault on college campuses
Inability to pay for healthcare reaches record high in U.S.
Science ‘storytelling’ urgently needed amid climate and biodiversity crisis
KAIST Develops Retinal Therapy to Restore Lost Vision
Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response
Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid
Low LDL cholesterol levels linked to reduced risk of dementia
Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients
Almost one in ten people surveyed report having been harmed by the NHS in the last three years
Enhancing light control with complex frequency excitations
New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients
New insight into factors associated with a common disease among dogs and humans
Illuminating single atoms for sustainable propylene production
New study finds Rocky Mountain snow contamination
Study examines lactation in critically ill patients
UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award
[Press-News.org] Domain walls as new information storage mediumVisualization of domain wall motion: Material defects do not impede wall motion at high velocities / Publication of findings in Nature Communications