We are studying the electronic structures of new and advanced materials. We are using synchrotron radiation to perform soft x-ray emission and absorption spectroscopy of systems like biomaterials, superconductors and transition metal compounds.

Robert Green

Robert Green

[robert.green@usask.ca]

Education

  • University of Saskatchewan
    Saskatoon, Saskatchewan
    B.E. Engineering Physics
    May 2009
  • University of Saskatchewan
    Saskatoon, Saskatchewan
    B.Sc. Computer Science
    May 2009
  • University of Saskatchewan
    Saskatoon, Saskatchewan
    Ph.D. Physics
    August 2013

Current Affiliation

Ph.D. Thesis

  • Transition Metal Impurities in Semiconductors: Induced Magnetism and Band Gap Engineering (link)

Research Projects

Material Science

My current work focuses on the field of spintronics, where conventional electronics are given an extra layer of dimensionality by adding control over the spin property of electrons. In particular, I am studying dilute magnetic semiconductors (DMS), where a traditional, non-magnetic semiconductor is doped with magnetic atoms to induce magnetism and therefore spin transport properties. These magnetic atoms are usually transition metals, which means these materials are ideal candidates for study with soft x-ray spectroscopy. By using X-ray Absorption Spectroscopy and X-ray Emission Spectroscopy, we can probe the local environment of the magnetic atoms to determine how they interact with the host material to induce magnetic effects.

Instrumentation

I have also been involved with the design and construction of the new inelastic scattering endstation on the REIXS beamline at the Canadian Light Source. A few of my contributions are the design of permanent magnet arrays that will be used for magnetic dichroism experiments, helping with the redesign of a preamplifier for the x-ray detector so it can meet the special constraints of its location, and assembling a mobile sample preparation chamber. I am currently assisting with the final assembly and commissioning of the endstation.

Awards

  • Saskatchewan Innovation and Opportunity Scholarship (Apr. 2012)
  • Canadian Light Source AUM Student Poster Award (Jun. 2011)
  • Advanced Light Source AUM Student Poster Award (Oct. 2010)
  • NSERC Postgraduate Scholarship, D3 (Sept. 2010)
  • NSERC Canada Graduate Scholarship, M (Sept. 2009)
  • U of S PEP Most Distinguished Graduate (May 2009)
  • NSERC Undergraduate Student Research Award (May 2009)
  • NSERC Undergraduate Student Research Award (May 2007)

Publications

View Robert's citations on Google Scholar Google Scholar
Researcher ID
  • I. Perez, J. A. McLeod, R. J. Green, R. Escamilla, V. Ortiz, and A. Moewes,
    Electronic structure of Co-substituted FeSe superconductor probed by soft x-ray spectroscopy and density functional theory,
    Physical Review B, 90, 014510 (2014).

  • T. D. Boyko, R. J. Green, A. Moewes, and T. Z. Regier,
    Measuring partial fluorescence yield using filtered detectors,
    Journal of Synchrotron Radiation, 21 (4), 716-721 (2014).

  • R. J. Green, D. Peak, A. J. Achkar, J. S. Tse, A. Moewes, D. Hawthorn, and T. Z. Regier,
    Comment on "State-dependent electron delocalization dynamics at the solute-solvent interface: Soft x-ray absorption spectroscopy and ab initio calculations",
    Physical Review Letters, 112, 129301 (2014).

  • R. J. Green, D. A. Zatsepin, D. J. St. Onge, E. Z. Kurmaev, N. V. Gavrilov, A. F. Zatsepin, and A. Moewes,
    Electronic band gap reduction and intense luminescence in Co and Mn ion-implanted SiO2,
    Journal of Applied Physics, 115, 103708 (2014).

  • J. A. McLeod, D. W. Boukhvalov, D. A. Zatsepin, R. J. Green, B. Leedahl, L. Cui, E. Z. Kurmaev, I. S. Zhidkov, L. Finkelstein, N. V. Gavrilov, S. O. Cholakh, and A. Moewes,
    Local structure of Fe impurity atoms in ZnO: bulk versus surface
    Journal of Physical Chemistry C, 118 (10), 5336-5345 (2014).

  • B. Leedahl, D. A. Zatsepin, D. W. Boukhvalov, R. J. Green, J. A. McLeod, S. S. Kim, E. Z. Kurmaev, I. S. Zhidkov, N. V. Gavrilov, S. O. Cholakh, and A. Moewes,
    Structural defects induced by Fe-ion implantation in TiO2
    Journal of Applied Physics, 115, 053711 (2014).

  • T. D. Boyko, R. J. Green, R. Dronskowski, and A. Moewes,
    Electronic band gap reduction in manganese carbodiimide: MnNCN,
    Journal of Physical Chemistry C, 117 (24), 12754-12761 (2013).

  • S. C. Das, R. J. Green, J. Podder, T. Z. Regier, G. S. Chang, and A. Moewes,
    Band gap tuning in ZnO through Ni doping via spray pyrolysis,
    Journal of Physical Chemistry C, 117 (24), 12745-12753 (2013).

  • R. J. Green, D. A. Zatsepin, A. Hunt, E. Z. Kurmaev, N. V. Gavrilov, and A. Moewes,
    The formation of Ti-O tetrahedra and band gap reduction in SiO2 via pulsed ion implantation,
    Journal of Applied Physics, 113, 103704 (2013).

  • R. J. Green, D. W. Boukhvalov, E. Z. Kurmaev, L. D. Finkelstein, H. W. Ho, K. B. Ruan, L. Wang, and A. Moewes,
    Room temperature ferromagnetism via unpaired dopant electrons and p-p coupling in carbon-doped In2O3: Experiment and theory,
    Physical Review B, 86, 115212 (2012).

  • R. J. Green, A. Hunt, D. A. Zatsepin, D. W. Boukhvalov, J. A. McLeod, E. Z. Kurmaev, N. A. Skorikov, N. V. Gavrilov, and A. Moewes,
    Interplay of ballistic and chemical effects in the formation of structural defects for Sn and Pb implanted silica,
    Journal of Non-Crystalline Solids, 358, 3187-3192 (2012).

  • J. A. McLeod, R. J. Green, E. Z. Kurmaev, N. Kumada, A. A. Belik, and A. Moewes,
    Band gap engineering in TiO2-based ternary oxides,
    Physical Review B, 85, 195201 (2012).

  • J. A. McLeod, A. Buling, R. J. Green, T. D. Boyko, N. A. Skorikov, E. Z. Kurmaev, M. Neumann, L. D. Finkelstein, N. Ni, A. Thaler, S. L. Bud'ko, P. C. Canfield, and A. Moewes,
    Effect of 3d doping on the electronic structure of BaFe2As2,
    Journal of Physics: Condensed Matter, 24, 215501 (2012).

  • D. A. Zatsepin, R. J. Green, A. Hunt, E. Z. Kurmaev, N. V. Gavrilov, and A. Moewes,
    Structural ordering in a silica glass matrix under Mn ion implantation,
    Journal of Physics: Condensed Matter, 24, 185402 (2012).

  • E. J. McDermott, E. Z. Kurmaev, T. D. Boyko, L. D. Finkelstein, R. J. Green, K. Maeda, K. Domen, and A. Moewes,
    Structural and band gap investigation of GaN:ZnO heterojunction solid solution photocatalyst probed by soft x-ray spectroscopy,
    Journal of Physical Chemistry C, 116 (14), 7694–7700 (2012).

  • J. A. McLeod, R. J. Green, N. A. Skorikov, L. D. Finkelstein, M. Abu-Samak, E. Z. Kurmaev, and A. Moewes,
    Valence structure of alkaline and post-transition metal oxides,
    Proc. SPIE 7940, 79400R (2011).

  • R. J. Green, G. S. Chang, X. Y. Zhang, A. Dinia, E. Z. Kurmaev, and A. Moewes,
    Identifying local dopant structures and their impact on magnetic properties in spintronics materials,
    Physical Review B, 83 (11), 115207 (2011).

  • A. Bouaine, R. J. Green, S. Colis, P. Bazylewski, G. S. Chang, A. Moewes, E. Z. Kurmaev, and A. Dinia,
    Appearance of ferromagnetism in Co-doped CeO2 diluted magnetic semiconductors prepared by solid state reaction,
    Journal of Physical Chemistry C, 115, 1556-1560 (2011).