English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Insights into the structural, electronic, and magnetic properties of Fe2-xTixO3/Fe2O3 thin films with x=0.44 grown on Al2O3 (0001)

MPS-Authors
There are no MPG-Authors available
External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Dennenwaldt, T., Lübbe, M., Winklhofer, M., Müller, A., Döblinger, M., Nabi, H. S., et al. (2015). Insights into the structural, electronic, and magnetic properties of Fe2-xTixO3/Fe2O3 thin films with x=0.44 grown on Al2O3 (0001). Journal of Materials Science, 50(1), 122-137. doi:10.1007/s10853-014-8572-x.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0024-B73D-0
Abstract
The interface between hematite (alpha-(Fe2O3)-O-III) and ilmenite ((FeTiO3)-Ti-II), a weak ferrimagnet and an antiferromagnet, respectively, has been suggested to be strongly ferrimagnetic due to the formation of a mixed valence layer of Fe2+/Fe3+ (1: 1 ratio) caused by compensation of charge mismatch at the chemically abrupt boundary. Here, we report for the first time direct experimental evidence for a chemically distinct layer emerging at heterointerfaces in the hematite-Ti-doped-hematite system. Using molecular beam epitaxy, we have grown thin films (similar to 25 nm thickness) of alpha-Fe2O3 on alpha-Al2O3 (0001) substrates, which were capped with a similar to 25 nm thick Fe2-xTixO3 layer (x = 0.44). An additional 3 nm cap of alpha-Fe2O3 was deposited on top. The films were structurally characterized in situ with surface X-ray diffraction, which showed a partial low index orientation relationship between film and substrate in terms of the [0001] axis and revealed two predominant domains with (0001)(Fe2O3) vertical bar vertical bar (0001)(Al2O3,) one with [10 (1) over bar0](Fe2O3) vertical bar vertical bar [10 (1) over bar0](Al2O3), and a twin domain with [01 (1) over bar0](Fe2O3) vertical bar vertical bar [10 (1) over bar0]Al2O3. Electron energy loss spectroscopy profiles across the Fe2-xTixO3/Fe2O3 interface show that FeFe2+/Fe3+ ratios peak right at the interface. This strongly suggests the formation of a chemically distinct interface layer, which might also be magnetically distinct as indicated by the observed magnetic enhancement in the Fe2-xTixO3/alpha-Fe2O3/Al2O3 system compared to the pure alpha-Fe2O3/Al2O3 system.