SEAGATE TECHNOLOGY IRELAND
Seagate is a worldwide leader in the design, manufacturing and marketing of hard disc drives, providing products for a wide-range of Enterprise, Desktop, Mobile Computing, and Consumer Electronics applications. Seagate’s business model leverages technology leadership and world-class manufacturing to deliver industry-leading innovation and quality to its global customers, and to be the low cost producer in all markets in which it participates. At Seagate’s Springtown wafer fabrication facility in Northern Ireland, the Company employs over 1400 people developing and manufacturing recording heads, which write information onto and read information from the recording disc inside a computer’s hard drive. The Springtown facility manufactures most of the heads for Seagate products and is the largest magnetism facility in Europe. Read sensors for magnetic recording can be considered as spin electronic devices, and Seagate is actively involved in developing new technology for data storage.
The faculty of physics at the University of Duisburg-Essen has about 500 physics students and more than 20 professors. One focal point of the faculty is experimental solid state physics. Heiko Wende is professor at the University of Duisburg-Essen at the faculty of physics since 2007. His group focuses on magnetic nanostructures consisting of ultrathin magnetic films, magnetic nanoparticles and magnetic molecules. The magnetic nanostructures and magnetic hybrid systems are prepared in his group by molecular beam epitaxy (MBE) under ultra-high vacuum (UHV) conditions (ultrathin films), by sublimation in situ in UHV (molecular spin hybrid systems) and by wet chemical approach (magnetic nanoparticles). The electronic and geometrical structures as well as the magnetic properties of these nanostructures are mainly studied by X-ray absorption and Mössbauer spectroscopy. The group of H. Wende has a long-standing expertise in the preparation and the investigation of magnetic nanostructures like multi-layer systems. Various MBE systems exist in his group. In addition to the X-ray absorption spectroscopy investigations at synchrotron radiation facilities the magnetic nanostructures are characterized in situ by electron diffraction (LEED, RHEED) Auger electron spectroscopy and X-ray photoelectron spectrosopy (XPS). Heiko Wende is a member of the Centre for Nanointegration Duisburg-Essen (CENIDE). In addition to the laboratory facilities of the group of Heiko Wende, CENIDE offers access to state-of-the art equipment for research of nanostructures utilizing transmission electron microscopy, a focused ion beam setup and cleanroom facilities.
The main involvement of Heiko Wende’s group will be the experimental validation of materials combinations that have been identified as potential candidates for new high moment materials by the theoretical investigations in Uppsala. By means of MBE, thin films with proper stoichiometry of the respective elements will be prepared under ultra high vacuum conditions at the Campus Duisburg. The magnetic properties will be studied element-specifically by means of X-ray absorption spectroscopy at synchrotron radiation facilities. The microscopic properties determined for these high moment materials can be directly compared to the DFT calculations performed in Uppsala. The specific analysis of the multilayers will be carried out in synchrotron radiation facilities especially by X-ray Magnetic Circular Dichroism (XMCD) as well as by magnetic Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS). The XMCD investigations of these films will reveal the element specific spin- and orbital moments including their relative orientation. For the case of Gd/Cr/Fe and Gd/Cr/FeCo multilayers the parallel coupling of the Gd and Fe spin moments will be tested by these measurements. These investigations will be complemented by magnetic characterization utilizing SQUID magnetometry, Mössbauer spectroscopy (for Fe-containing systems) and X-ray photoemission spectroscopy (XPS) in the laboratory at the campus in Duisburg. The experimentally determined magnetic moments will be compared to the DFT calculations. Thereby, the high moment behavior for these systems can be validated. In a feedback loop the experimental moments will help to validate the theoretical predictions. This will yield optimized theoretical modeling of advanced high moment materials which will again be tested at the Campus Duisburg as described above.
Dr. Biplab Sanyal is a Senior Lecturer and Docent in Dept. of Physics and Astronomy at Uppsala University. He belongs to the Division of Materials Theory, which comprises more than 50 researchers engaged in the cutting edge problems of computational materials science.
Dr. Sanyal obtained his Ph.D. in Physics from S. N. Bose National Centre for Basic Sciences, Kolkata under the supervision of Prof. Abhijit Mookerjee in 2000. His topic was the development of theory of random alloys in bulk and low dimensions. He was a postdoc in Brock University, Canada from 1999 to 2000 working on phase stability of alloys and invar properties with Prof. S. K. Bose.
Subsequently, Dr. Sanyal was a postdoc in Uppsala University from 2000 to 2003 working on spintronic materials, ferromagnet-semiconductor interfaces etc. followed by an assistant professorship from 2003 to 2007, after which he became an associate professor.
Dr. Sanyal’s expertise is in various aspects of complex magnetism in technologically relevant materials, multiferroic oxides, graphene, functional organometallics etc. using first principles theory, sometimes combined with Monte Carlo, molecular dynamics and atomistic spin dynamics methods. He is the author of around 145 scientific papers with h-index 25 and more than 2600 citations, and has strong collaborations with various groups in India, Germany, Brazil, Netherlands and Italy.
In this project, Dr. Sanyal’s role is to identify suitable materials combinations to realize high saturation magnetic moments. His team will employ state-of-the-art first principles electronic structure theories to study combinations of rare earth (RE) and transition metal (TM) elements in the form of bulk, surfaces, interfaces and nanostructures to suggest suitable RE-TM composites to the experimentalists involved in the project. The methods will primarily involve Density Functional Theory (DFT) along with Monte-Carlo simulations.
Dr. Sanyal’s team has three postdocs, Dr. Carmine Autieri, Dr. Hakkim Vovusha and Dr. Manoj Kumar Yadav.