Physical properties in thin films of iron oxides.

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Microelectron. J.

DOI:https://doi.org/10.1016/j.mejo.2008.01.054· OSTI ID:944037

Uribe, J D; Osorio, J; Barrero, C A; Girata, D; Morales, A L; Hoffmann, A

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 Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 944037
• Report Number(s): ANL/MSD/JA-63026
• Journal Information: Microelectron. J., Journal Name: Microelectron. J. Journal Issue: 11 ; 2008 Vol. 39; ISSN MICEB9; ISSN 0026-2692
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
GRAIN SIZE
HEMATITE
IRON OXIDES
ISOMER SHIFT
MAGNETITE
MAGNETIZATION
MAGNETRONS
MOESSBAUER EFFECT
MONOCRYSTALS
MORPHOLOGY
PHYSICAL PROPERTIES
ROUGHNESS
SPECTRA
STAINLESS STEELS
SUBSTRATES
THIN FILMS
VECTORS
X-RAY DIFFRACTION