1 / 2

Giant Magnetic Coercivity in Rare-Earth-Free Mn x Ga Donald Heiman , Northeastern University, DMR 0907007.

ianthe
Télécharger la présentation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Giant Magnetic Coercivity in Rare-Earth-Free MnxGaDonald Heiman, Northeastern University, DMR 0907007 We have synthesized a novel magnetic material that has a Giant Coercive Field at room temperature. The Heusler ferrimagnet MnxGa is found to have one of the highest coercive fields for a magnetic material that is free of rare earth elements. The exceedingly large coercivity (oHc=2.4 tesla) arises from a combination of an exceptionally large crystal anisotropy and strong nanoscale structural disorder. In addition, the large coercivity is also present in the electrical properties through the Anomalous Hall Effect (AHE). The high coercivity in the AHE is uniquely valuable since it transforms the magnetic properties into the electronic domain where it can have an impact on magnetoelectronics. This rare-earth-free material has excellent prospects for nanoelectronics, as well as high-performance nanocomposite permanent magnets for applications in electric vehicles and wind turbines. Magnetization of MnxGa showing Giant Coercive Field of 2.4 tesla at room temperature; Anomalous Hall Effect in resistivity.

  2. Undergraduate Research Giant Magnetic Coercivity in Rare-Earth-Free MnxGa Donald Heiman, Northeastern University, DMR 0907007 Most of the work on the Giant Coercivity in MnxGa was performed by undergraduate students. Two of these undergraduates (Tom Nummy and Tom Cardinal) are coauthors on a paper that was submitted Physical Review, and Tom Nummy was the lead author. Tom Nummy was responsible for synthesizing the films via molecular beam epitaxy, and the magnetic and conductivity measurements. Tom Cardinal was responsible for characterizing the nanostructures and strain contributions with x-ray diffraction experiments. A high school student (Tyler Kehne) contributed to the project during his senior internship using the magneto-optic Kerr effect. One of the great strengths of Northeastern University is their Co-op program where students spend three 6-month periods working in industry or a research lab. The Toms worked on this project as Co-op students partially supported by an NSF-REU supplement. T.J. Nummy, S.P Bennett, T. Cardinal, W.B. Nowak, and D. Heiman, Phys. Rev. B (submitted, 2011).

More Related