Effect of intermediate valence in the XMCD spectra of greigite (Fe3S4)

Datum

20.04.2018

Zeit

14:00 - 15:00

Sprecher

Dr. Javier Fernández-Rodriguez

Zugehörigkeit

Magnetic Spectroscopy Group, Diamond Light Source, Didcot, UK

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien, Physik

Host

Grit Rötzer

Beschreibung

Greigite (Fe3S4) is a mineral that crystallizes in the same inverse spinel crystallographic structure as its counterpart oxide magnetite (Fe3O4). Although greigite and magnetite have similar structural and magnetic properties, the results of spectroscopy for greigite evidence important differences in magnetic and electronic structure. In particular, the measured shape of the XMCD spectra for greigite [1,2] changes significatively from the case of magnetite. We discuss a ligand-field model including the effect of the intermediate valence between Fe2+ and Fe3+ for greigite. Using this model we can give a good agreement with the measured XAS and XMCD. References [1] L. Chang, R. A. D. Pattrick, G. van der Laan, V. S. Coker, and A. P. Roberts, The Canadian Mineralogist 50, 667 (2012). [2] R. A. Pattrick, V. S. Coker, M. Akhtar, M. A. Malik, E. Lewis, S. Haigh, P. O’Brien, P. C. Shafer, and G. van der Laan, Mineralogical Magazine 81, 857 (2017). .

Links

• Seminars at the IFW

Letztmalig verändert: 20.04.2018, 09:48:16