AVS 61st International Symposium & Exhibition
    Magnetic Interfaces and Nanostructures Tuesday Sessions
       Session MI+MG-TuM

Paper MI+MG-TuM10
Growth and Properties of Skyrmionic MnSi Nanowires and Thin Film on Silicon

Tuesday, November 11, 2014, 11:00 am, Room 311

Session: Advanced Materials Discovery 
Presenter: Jieyu Yi, University of Tennessee
Authors: J. Yi, University of Tennessee
S.W. Tang, University of Tennessee
I.I. Kravchenko, Oak Ridge National Laboratory
G.X. Cao, Oak Ridge National Laboratory
D.G. Mandrus, University of Tennessee
Z. Gai, Oak Ridge National Laboratory
Correspondent: Click to Email

Magnetic skyrmion lattice, a vortex-like spin texture recently observed in chiral magnets, is of great interest to future spin-electronic data storage and other information technology applications . The origin of the magnetic skyrmion phase can be traced to the anti-symmetric Dzyaloshinski-Moriya (DM) interaction that is allowed in space groups lacking inversion symmetry. The combined effect of a large ferromagnetic exchange and a weak DM interaction is to twist the magnetization into a long-period spiral that can be tens to hundreds of nanometers in length. As these spirals are only weakly bound to the underlying lattice in cubic systems, they can be readily manipulated with modest applied fields. Prototypical materials with the skyrmion ordering are those compounds with B20 structure, like MnSi and FeGe. The skyrmion lattice in MnSi appears in a small region (known as the A phase) of the H-T phase diagram in bulk samples, but in 2D samples like thin films the skyrmion phase is much more robust. It is of great interest to determine the properties of the skyrmion phase in quasi-1D nanowires and 2D thin films. If skyrmion ordering can persist in one-dimensional MnSi nanowires and 2D films, then these systems may be very promising for spintronics applications as the magnetic domains and individual skymions could be manipulated with small currents. We have systematically explored the synthesis of single crystal MnSi nanowires via controlled oxide-assisted chemical vapor deposition and observed a characteristic signature of skyrmion magnetic ordering in MnSi nanowires. The SiO2 layer pla ys a key role for the high yield, correct stoichiometric and crystalline growth of the B20 MnSi nanowires. A growth phase diagram was constructed. For the thin films, an unique growth receipt was developed for the growth of high quality of thin films. The structure and magnetic properties of the films at different thickness were studied.