Center for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo
Professor Helmer Fjellvåg is the Head of the Group of Inorganic materials chemistry at the Department of Chemistry at University of Oslo. Professor Fjellvåg has over 470 publications in peer-reviewed journals, and has adviced 41 master, 21 PhD and 30 postdocs/researchers during his time at UiO. He is the holder of Birkeland innovation award, co-founder Baldor Coating AS, and a Member of the Norwegian Academy of Science and Letters. His expertise and knowledge base is in materials/solid state chemistry, nanomaterials and thin films; soft chemistry routes towards novel compounds, model materials, studies of substitutions and defects; atomic layer deposition (ALD) routes for complex oxides and novel systems; intermetallics, magnetostructural phase transitions ; use of synchrotron and neutron radiation for in-situ studies, structure solving and refinement, disorder; physical and thermal characterization; magnetization, resistivity, heat capacity and in computational materials science; semiconductors, oxides, battery materials, magnetic materials.
His laboratory facilities include a materials synthesis laboratory (solvothermal, nanomaterial, ALD, high temperature, transport reactions), a battery laboratory (galvanostatic cycling, impedance spectroscopy, in situ diffraction, coatings), and a X-ray laboratory (national RECX infrastructure); high throughput, high/low-T, in operando, thin films, reflectometer, single crystals, SAXS.
The title of Professor Fjellvåg's seminar is:
"Powder X-ray diffraction - an important tool for phase analysis of reactants and products"
Powder diffraction - PXRD - is a powerful tool, both alone, and even more as a complementary technique to XRF elemental analysis. PXRD and XRD has many aspects. The presentation will address how XRD is used as a chemical information gatherer, how XRD instrumental technology is in change with smaller table-top instruments, and the presentation will also discuss another aspect of XRD, how, in tomography, diffraction is used for material imaging.
Essentially, XRD gives information on what chemical species are present; any process and chemical reaction stages can be studied if samples can be secured, with reactants and products. The presentation will give examples from work with the powerful Rietveld methodology for characterization, where actual crystallographic models for all chemical species of detectable concentrationsare included, giving not only concentrations but also material structure and even unit cell shifts.