Talks

• Frá Marsgransking til Myndlan á Setrinum ella Optimering av spinstøðuorku í nanobitlum. Jari í Hjøllum. NVD 50 ár. 18. Nov. 2022 Kongshøll, Fróðskaparsetur Føroya.
• Endamáls-drivin verklig undirvísing í alisfrøði (Objective-based experiments in physics teaching). Jari í Hjøllum & Ian G. Bearden,Vísindavøka 2022, sep. 2022, Løkshøll.
• 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.
• Electron holography - Hovedfagskolloqium (en: Major Colloqium), Jari í Hjøllum. 2004. Supervisor: Erik Johnson, University of Copenhagen.

Papers

• Nanocriticality in the magnetic phase transition of CoO nanoparticles. Machteld E. Kamminga, Jonas Okkels Birk, Jari í Hjøllum, Henrik Jacobsen, Jakob Lass, Thorbjørn L. Koch, Niels B. Christensen, Christof Niedermayer, Lukas Keller, Luise Theil Kuhn, Elisabeth T. Ulrikkeholm, Erik Brok, Cathrine Frandsen, Kim Lefmann.Phys. Rev. B, 107, 6, 064424, Feb. 2023. doi:10.1103/PhysRevB.107.064424
• 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.
  
  
• Fit;o) - A Mössbauer spectrum fitting program. Jari í Hjøllum and Morten Bo Madsen. arXiv:0912.0449v1 (2009).

Workshops

• Ian G. Bearden & Jari í Hjøllum. Building/using an DIY gamma detector. Danish Physical Society annual meeting 2018.
• Ian G. Bearden & Jari í Hjøllum. Using the Raspberry Pi as an alpha particle detector. Danish Physical Society annual meeting 2017.

Posters

1. Investigations of the Antiferromagnetic Order Parameter in Nano-Sized YBCO Particles -
   Presented at: ICNS2009 - International Conference on Neutron Scattering 2009, May 3-7, 2009, Knoxville, TN, USA.
2. Nano-criticality in small CoO particles -
   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 -
   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 -
   Presented at: DFS 2006, DK.
5. Fit;o) - A Mössbauer Spectrum Fitting Program -
   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. Water and magnetic properties of dust on Mars - Results from the Mars Exploration Rovers
   J. í Hjøllum, K. Leer, P. Bertelsen, M. B. Madsen.
   Presented at: DFS 2004, DK.
8. Magnetic properties of iron oxide nano-particles fabricated by the inverse micellar method -
   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

Coauthored Posters

1. K. Leer, J. í Hjollum, P. Bertelsen, W. Goetz, K. Kinch, S. F. Hviid, J.
   M. Knudsen, M. B. Madsen. Magnetic properties of dust on Mars - Results
   from the Mars Exploration Rovers, Presented at: American Geophysical
   Union, Fall Meeting 2004 link
2. Andreasen, A., Vegge, T., Hjøllum, J. Í., Engberg, D., & Lefmann, K.
   (2004). A quasi-elastic neutron scattering study of H-motion in complex
   sodium aluminum hydride (poster). Poster session presented at 2nd Annual
   Meeting in the Copenhagen Graduate School for Nanoscience and Nanotechnology,
   Copenhagen, Denmark. link

Presentations:

• KT, Verkfrøði & Lívfrøði – øki í vøkstri. Jari í Hjøllum. Framløga á Markleys Útbúgving 2022.

• Numerical Modelling
• Numerical Simulation
• Magnetic properties of iron oxide nano particles.
• Magnetic properties of nano-sized HTC superconductors.
• Mössbauer Spectroscopy.
• Neutron Scattering / Diffraction.
• Instrument / Measurement Software.