Physical properties in thin films of iron oxides.
We have grown hematite ({alpha}-Fe{sub 2}O{sub 3}) thin films on stainless steel substrates and magnetite (Fe{sub 3}O{sub 4}) thin films on (0 0 1)-Si single crystal substrates by a RF magnetron sputtering process. {alpha}-Fe{sub 2}O{sub 3} thin films were grown in an Ar atmosphere at substrate temperatures around 400 C, and Fe{sub 3}O{sub 4} thin films in an Ar/O{sub 2} reactive atmosphere at substrate temperatures around 500 C. Conversion electron Moessbauer (CEM) spectra of {alpha}-Fe{sub 2}O{sub 3} thin films exhibit values for hyperfine parameter characteristic of the hematite stoichiometric phase in the weak ferromagnetic state [R.E. Vandenberghe, in: Moessbauer Spectroscopy and Applications in Geology, University Gent, Belgium, 1990. [1]]. Furthermore, the relative line intensity ratio suggests that the magnetization vector of the polycrystalline film is aligned preferentially parallel to the surface. The CEM spectra of Fe{sub 3}O{sub 4} thin films show the presence of only the stoichiometric phase, and the values for the hyperfine fields and isomer shifts of the A and B sites are consistent with bulk Fe{sub 3}O{sub 4} [1]. The X-ray diffraction (XRD) pattern of the polycrystalline thin films also corresponds to {alpha}-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} [JCPDS, X-ray diffraction data cards, 2001. [2]]. The samples were also analyzed by atomic force microscopy (AFM) and they reveal a grain morphology common for polycrystalline films. We found an average grain size of 211 nm and surface roughness of 45 nm in {alpha}-Fe{sub 2}O{sub 3} films and an average grain size of 148 nm and surface roughness of 1.2 nm in Fe{sub 3}O{sub 4} films.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 944037
- Report Number(s):
- ANL/MSD/JA-63026; MICEB9; TRN: US200902%%539
- Journal Information:
- Microelectron. J., Vol. 39, Issue 11 ; 2008; ISSN 0026-2692
- Country of Publication:
- United States
- Language:
- ENGLISH
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