NiO/Fe(001): Magnetic anisotropy, exchange bias, and interface structure

Journal Article · Fri Jun 21 00:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4811528· OSTI ID:22163059

Mlynczak, E. ^[1]; Luches, P. ^[2]; Valeri, S. ^[2]; Korecki, J. ^[1]

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1. Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow (Poland)
2. S3, Istituto Nanoscienze-CNR, Via G. Campi 213/a, I-41125 Modena (Italy)

The magnetic and structural properties of NiO/Fe epitaxial bilayers grown on MgO(001) were studied using magnetooptic Kerr effect (MOKE) and conversion electron Moessbauer spectroscopy (CEMS). The bilayers were prepared under ultra high vacuum conditions using molecular beam epitaxy with oblique deposition. Two systems were compared: one showing the exchange bias (100ML-NiO/24ML-Fe), ML stands for a monolayer, and another where the exchange bias was not observed (50ML-NiO/50ML-Fe). For both, the magnetic anisotropy was found to be complex, yet dominated by the growth-induced uniaxial anisotropy. The training effect was observed for the 100ML-NiO/24ML-Fe system and quantitatively described using the spin glass model. The composition and magnetic state of the interfacial Fe layers were studied using {sup 57}Fe-CEMS. An iron oxide phase (Fe{sup 3+}{sub 4}Fe{sup 2+}{sub 1}O{sub 7}), as thick as 31 A, was identified at the NiO/Fe interface in the as-deposited samples. The ferrimagnetic nature of the interfacial iron oxide film explains the complex magnetic anisotropy observed in the samples.

• OSTI ID: 22163059
• Journal Information: Journal of Applied Physics, Vol. 113, Issue 23; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
ELECTRON SPECTRA
EXCHANGE INTERACTIONS
FERRIMAGNETIC MATERIALS
FILMS
INTERFACES
IRON
IRON 57
IRON OXIDES
KERR EFFECT
LAYERS
MAGNESIUM OXIDES
MAGNETISM
MAGNETO-OPTICAL EFFECTS
MOESSBAUER EFFECT
MOLECULAR BEAM EPITAXY
NICKEL OXIDES
SPECTROSCOPY
SPIN GLASS STATE
VACUUM COATING