Session T15: Focus Session: Spins in Semiconductors - III-V Magnetic Semiconductors

2:30 PM–5:30 PM, Wednesday, March 23, 2011
Room: D171

Sponsoring Units: DMP GMAG FIAP
Chair: Ken Burch, University of Toronto

Abstract ID: BAPS.2011.MAR.T15.7

Abstract: T15.00007 : Structural and Magnetic Characteristics of p-GaAs/MnAs Nanocluster Hybrids

4:30 PM–4:42 PM

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Authors:

  David Rench
    (Department of Physics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA)

  Peter Schiffer
    (Department of Physics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA)

  Nitin Samarth
    (Department of Physics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA)

A possible route towards semiconductor spintronic devices involves the controlled synthesis of hybrid materials that combine ferromagnetic (FM) nanoclusters within a doped semiconductor host lattice. We use molecular beam epitaxy of (Ga,Mn,Be)As followed by in situ annealing to synthesize a systematic set of samples wherein FM nanoclusters are embedded in a p-GaAs matrix. High resolution transmission electron microscopy (HRTEM) and magnetometry demonstrate our ability to reproducibly synthesize two distinct classes of materials: (a) type I samples consisting of uniformly distributed, small clusters ($\sim $6 nm); (b) type II samples consisting of a bimodal distribution of small ($\sim $6 nm) and large ($\sim $25 nm) clusters. HRTEM studies show that while the large clusters are clearly MnAs with NiAs structure, the smaller clusters are possibly zinc blende in structure but with a more complex composition. We analyze the magnetic behavior of these two classes of samples and show measurements of their transport properties. Supported by the ONR-MURI program.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.MAR.T15.7