Magnetic states at the surface of α-Fe2 O3 thin films doped with Ti, Zn, or Sn

David S. Ellis, Eugen Weschke, Asaf Kay, Daniel A. Grave, Kirtiman Deo Malviya, Hadar Mor, Frank M.F. De Groot, Hen Dotan, Avner Rothschild

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

The spin states at the surface of epitaxial thin films of hematite, both undoped and doped with 1% Ti, Sn, or Zn, respectively, were probed with x-ray magnetic linear dichroism (XMLD) spectroscopy. Morin transitions were observed for the undoped (TM≈200 K) and Sn-doped (TM≈300 K) cases, while Zn- and Ti-doped samples were always in the high- and low-temperature phases, respectively. In contrast to what has been reported for bulk hematite doped with the tetravalent ions Sn4+ and Ti4+, for which TM dramatically decreases, these dopants substantially increase TM in thin films, far exceeding the bulk values. The normalized Fe LII-edge dichroism for T<TM does not strongly depend on doping or temperature, except for an apparent increase of the peak amplitudes for T<100 K. We observed magnetic field-induced inversions of the dichroism peaks. By applying a magnetic field of 6.5 T on the Ti-doped sample, a transition into the T>TM state was achieved. The temperature dependence of the critical field for the Sn-doped sample was characterized in detail. It was demonstrated the sample-to-sample variations of the Fe LIII-edge spectra were, for the most part, determined solely by the spin orientation state. Calculations of the polarization-dependent spectra based on a spin-multiplet model were in reasonable agreement with the experiment and showed a mixed excitation character of the peak structures.

Original languageEnglish
Article number094426
JournalPhysical Review B
Volume96
Issue number9
DOIs
StatePublished - 20 Sep 2017
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Magnetic states at the surface of α-Fe2 O3 thin films doped with Ti, Zn, or Sn'. Together they form a unique fingerprint.

Cite this