Name: Jari í Hjøllum
  • Ph.D. in Physics, 2008
  • Cand. Scient./Master in Physics, 2004
  • Bachelor in Physics and Mathematics, 2001.
Areas of research/interest:
  • Mars Exploration
  • Møssbauer spectroscopy
  • Nano magnetism
  • Iron Oxides
  • Scientific Programming/Simulation
  • Neutron scattering
  • MuSR - Muon Spin Rotatio
  • Instrumentation
  • Fuel cell development
Member of:

Thesis works


  1. Overview of the magnetic properties experiments on the Mars Exploration Rovers. M. B. Madsen, W. Goetz, P. Bertelsen, C. S. Binau, F. Folkmann, H. P. Gunnlaugsson, J. í Hjøllum, S. F. Hviid, J. Jensen, K. M. Kinch, K. Leer, D. E. Madsen, J. Merrison, M. Olsen, H. M. Arneson, J. F. Bell III, R. Gellert, K. E. Herkenhoff,8 J. R. Johnson,8 M. J. Johnson,5 G. Klingelhöfer, E. McCartney, D. W. Ming, R. V. Morris, J. B. Proton, D. Rodionov, M. Sims, S. W. Squyres, T. Wdowiak and A. S. Yen. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114, 2009. doi:10.1029/2008JE003098.

  2. Fit;o) - A Mössbauer spectrum fitting program. Jari í Hjøllum and Morten Bo Madsen. arXiv:0912.0449v1 (Submitted on 2 Dec 2009). Download.

Conference contributions


  1. Building/using an DIY gamma detektor. DFS 2018.
  2. Using the Raspberry Pi as an alpha particle detector. DFS 2017.


  1. Nano-criticality in small CoO particles. - Jari í Hjøllum, Jonas O. Birk, Kim Lefmann, Niels B. Christensen, Christof Niedermayer, Cathrine Frandsen. Danish Physical Society 2007. Awarded best PhD talk.
  2. Electron holography - Hovedfagskolloqium (en: Major Colloqium), 2004. Supervisor: Erik Johnson, University of Copenhagen.


  1. Investigations of the Antiferromagnetic Order Parameter in Nano-Sized YBCO Particles - Download
    Presented at: ICNS2009 - International Conference on Neutron Scattering 2009, May 3-7, 2009, Knoxville, TN, USA.
  2. Nano-criticality in small CoO particles - Download
    Presented at: ECNS 2007 - European Conference on Neutron Scattering 2007, June 25-29, Lund, Sweden.
  3. Investigations of the antiferromagnetic phase of YBCO nano-particles - Download
    Presented at: First CoMePhS Workshop on PHASE SEPARATION IN ELECTRONIC SYSTEMS Crete - Greece, October 29 - November 4, 2006.
  4. Magnetic Properties of Magnetite Nano-Particles Manufactured by Reverse Micelles - Download
    Presented at: DFS 2006, DK.
  5. Fit;o) - A Mössbauer Spectrum Fitting Program - Download
    Presented at: DFS 2006, DK.
  6. Neutron scattering investigations of the antiferromagnetic phase of YBCO nano-particles - Download
    Presented at:
    • ICNS 2005, Aus, nov-dec 2005
    • DFS 2005, DK
  7. Magnetic properties of dust on Mars - Results from the Mars Exploration Rovers,
    K. Leer, J. í Hjollum, P. Bertelsen, W. Goetz, K. Kinch, S. F. Hviid, J. M. Knudsen, M. B. Madsen. Link
    Presented at: American Geophysical Union, Fall Meeting 2004
  8. Water and magnetic properties of dust on Mars - Results from the Mars Exploration Rovers
    J. í Hjøllum, K. Leer, P. Bertelsen, M. B. Madsen. Download
    Presented at: DFS 2004, DK.
  9. Magnetic properties of iron oxide nano-particles fabricated by the inverse micellar method - download.
    Presented at:
    • Annual meeting of Danish Physical Society 2003, Nyborg, Denmark, May 2003.
    • International Conference on Magnetism, Rome, july 2003.
    • Risø international symposium on materials science, superconductivety and magnetism, Roskilde, august, 2003.

Soft science publications

Scientific programming

  • Fit ;o) an analysis program for Moessbauer spectroscopy, developed by me.
  • konvert spm to exp for Moessbauer spectroscopy with PCA2 or PCA3. Should be used with MacFit programme.

My old science page, in faroese :-( .