Magnetic and Structural Properties of Mn$_{\mathrm{3}}$Ge$_{\mathrm{\thinspace }}$Nanoparticles

ORAL

Abstract

In this work, we have investigated the magnetic and structural properties of Mn$_{\mathrm{3}}$Ge nanoparticles prepared by the cluster-beam deposition technique. The composition, crystal structure and magnetic properties of the nanoparticles have been characterized by energy dispersive x-ray spectroscopy (EDS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM) and magnetometry measurements with the PPMS. Particles made with 1.5 Torr Argon pressure and power of 60 W have an average size of 13 nm and a highly disordered crystal structure. However, after a short annealing at 700 $^{\mathrm{o}}$C, the particle's structure is transformed to the hexagonal Ni$_{\mathrm{3}}$Sn-type structure with space group P6$_{\mathrm{3}}$/mmc(194) which is the same as in bulk. Hysteresis loop measurements showed that the annealed particles are ferromagnetic at room temperature showing a coercivity of 0.3 kOe at 50 K. The effects of particle size and temperature on the magnetic and structural properties are currently being studied and the results will be reported and discussed.

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Authors

  • Onur Tosun

    Department of Physics&Astronomy, University of Delaware

  • Balamurugan Balasubramanian

    Department of Physics&Astronomy, University of Nebraska, Lincoln

  • Ralph Skomski

    Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Nebraska, Department of Physics&Astronomy, University of Nebraska, Lincoln, University of Nebraska, Lincoln

  • David Sellmyer

    Department of Physics&Astronomy, University of Nebraska, Lincoln, NE Ctr for Matls & Nanosci, Univ. of Nebraska

  • George C. Hadjipanayis

    Department of Physics&Astronomy, University of Delaware