by Staff Writers
Berlin, Germany (SPX) Aug 29, 2017
This is an important clue for our theoretical understanding of optically controlled magnetic data storage media. The findings are published at August 25th in the journal Scientific Reports.
The demands placed on digital storage media are continuously increasing. Rapidly increasing quantities of data and new technological applications demand memory that can store large amounts of information in very little space and permit this information to be utilised dependably with high access speeds.
Re-writeable magnetic data storage devices using laser light appear to have especially good prospects. Researchers have been working on this new technology for several years. "However, there are still unresolved questions about the fundamental mechanisms and the exact manner in which optically controlled magnetic storage devices operate", says Dr. Florian Kronast, assistant head of the Materials for Green Spintronics department at the Helmholtz-Zentrum Berlin (HZB).
A research team led by him has now succeeded in making an important step toward better understanding of this very promising storage technology. The scientists were able to empirically establish for the first time that the warming of the storage material by the energy of the laser light plays an instrumental role when toggling the magnetisation alignments and that the change in the material only takes place under certain conditions.
Making precise measurements in tiny laser spots
"That is far less than was usual in prior experiments", says HZB scientist Ashima Arora, first author of the study. And it provided the researchers with unsurpassed detail resolution for studying the phenomena. The images of the magnetic domains in the alloy that the team created with the help of X-rays from the BESSY II synchrotron radiation source revealed fine features that themselves were only 30 nanometres in size.
The crucial thing occurs in the boundary ring
"It is only there that the toggling of magnetic properties can proceed, permitting a device to store re-writeable data", explains Arora.
Surprising influence of the layer thickness
An additional effect contributes to better understanding the physical processes that are important in this phenomenon, which researchers at HZB unexpectedly observed for the first time. The way the toggling of the magnetisations happens is highly dependent on the layer thickness of the material irradiated by the laser. It changes over an interval of 10 to 20 nanometres thickness.
"This is a clear indication that two contrasting mechanisms are involved and compete with one another", Kronast explains. He and his team suspect two complex physical effects for this. To confirm their suspicions, though, further empirical and theoretical studies are necessary.
The findings are published in Scientific Reports (DOI 10.1038/s41598-017-09615-1): "Spatially resolved investigation of all optical magnetization switching in TbFe alloys". Ashima Arora, Mohammad-Assaad Mawass, Oliver Sandig, Chen Luo, Ahmet A. Unal, Florian Radu, Dergio Valencia, Florian Kronast.
Seoul, South Korea (SPX) Aug 23, 2017
Inevitably, large stars at the end of their life collapse under the gigantic force of gravity, turning into black holes. We could cunningly ask if there is a way to delay this process; postpone the death of the star. While investigating "anti-aging therapy" of large stars, researchers at the Center for the Theoretical Physics of the Universe, within the Institute for Basic Science (IBS) co ... read more
Helmholtz-Zentrum Berlin fur Materialien und Energie
Space Technology News - Applications and Research
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|