Effect of confinement on spin polarization and magnetism of Co$_{2}$Si nanoclusters

ORAL

Abstract

Size-modified electronic structure and surface effects can lead to unusual magnetic ordering, modified ordering temperatures, and different spin structures in nanoclusters as compared to the corresponding bulk alloys. Thus nanoclusters can be used as building blocks to create new complex magnetic nanostructures for potential applications.\footnote{B. Balamurugan, D.J. Sellmyer et al. \textit{Sci. Rep}. \textbf{4}, 6265 (2014); \textit{Adv. Mater.} \textbf{25}, 6089, (2013); \textit{Appl. Phys. Lett.} \textbf{101}, 122407 (2012).} We show room-temperature ferromagnetic ordering in Co$_{2}$Si nanoclusters with relatively large magnetic moments (0.49 $\mu_{\mathrm{B}}$/Co at 300 K and 0.70 $\mu_{\mathrm{B}}$/Co at 10 K) and magnetocrystalline anisotropy ($K_{1} \approx $ 4 Mergs/cm$^{3}$ at 10 K), as contrasted to very weak itinerant magnetism in bulk Co$_{2}$Si (0.001 $\mu_{\mathrm{B}}$/Co at 300 K and 0.072 $\mu_{\mathrm{B}}$/Co at 10 K). The DFT and analytical model calculations explain the size-dependence of the observed magnetic moments on the size of Co$_{2}$Si nanoclusters, which vary from 0.6 to 30 nm, by a surface-induced spin polarization of nanoclusters.

*This research is supported by U.S. DOE-BES-DMSE (Grant No. DE-FG02-04ER46152) and NCMN.

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Authors

  • David Sellmyer

    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588
    • Nebraska Center for Materials and Nanosceince and Department of Physics and Astronomy, University of Nebraska
    • NCMN, University of Nebraska, Lincoln, NE 68588
    • Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE
    • University of Nebraska, Lincoln, NE 68588

  • Balamurugan Balasubramanian

    • NCMN, University of Nebraska, Lincoln, NE 68588

  • Priyanka Manchanda

    • NCMN, University of Nebraska, Lincoln, NE 68588

  • Ralph Skomski

    • NCMN, University of Nebraska, Lincoln, NE 68588

  • Pinaki Mukherjee

    • NCMN, University of Nebraska, Lincoln, NE 68588

  • Bhaskar Das

    • NCMN, University of Nebraska, Lincoln, NE 68588

  • George Hadjipanayis

    • University of Delaware, Newark, DE 19716