The dipole moment of the spin density as a local indicator for phase transitions
2014 (English)In: Scientific Reports, ISSN 2045-2322, Vol. 4, 5760- p.Article in journal (Refereed) Published
The intra-atomic magnetic dipole moment - frequently called < T-z > term - plays an important role in the determination of spin magnetic moments by x-ray absorption spectroscopy for systems with nonspherical spin density distributions. In this work, we present the dipole moment as a sensitive monitor to changes in the electronic structure in the vicinity of a phase transiton. In particular, we studied the dipole moment at the Fe2+ and Fe3+ sites of magnetite as an indicator for the Verwey transition by a combination of x-ray magnetic circular dichroism and density functional theory. Our experimental results prove that there exists a local change in the electronic structure at temperatures above the Verwey transition correlated to the known spin reorientation. Furthermore, it is shown that measurement of the dipole moment is a powerful tool to observe this transition in small magnetite nanoparticles for which it is usually screened by blocking effects in classical magnetometry.
Place, publisher, year, edition, pages
2014. Vol. 4, 5760- p.
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:uu:diva-229027DOI: 10.1038/srep05760ISI: 000339157000003OAI: oai:DiVA.org:uu-229027DiVA: diva2:735391