Oxide shell reduction and magnetic property changes in core-shell Fe nanoclusters under ion irradiation

Journal Article · Wed May 07 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4862520· OSTI ID:22273878

Sundararajan, Jennifer A.; Kaur, Maninder; Qiang, You ^[1]; Jiang, Weilin ^[2]; McCloy, John S. ^[3]

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1. Department of Physics, University of Idaho, Moscow, Idaho 83844 (United States)
2. Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)
3. School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164 (United States)

Ion irradiation effects are studied on the Fe-based core-shell nanocluster (NC) films with core as Fe and shell as Fe{sub 3}O{sub 4}/Fe{sub 3}N. These NC films were deposited on Si substrates to thickness of ∼0.5 μm using a NC deposition system. The films were irradiated at room temperature with 5.5 MeV Si{sup 2+} ions to ion fluences of 10{sup 15} and 10{sup 16} ions/cm{sup 2}. It is found that the irradiation induces grain growth, Fe valence reduction in the shell, and crystallization or growth of Fe{sub 3}N. The film retained its Fe-core and its ferromagnetic properties after irradiation. The nature and mechanism of oxide shell reduction and composition dependence after irradiation were studied by synthesizing additional NC films of Fe{sub 3}O{sub 4} and FeO + Fe{sub 3}N and irradiating them under the same conditions. The presence of nanocrystalline Fe is found to be a major factor for the oxide shell reduction. The surface morphologies of these films show dramatic changes in the microstructures due to cluster growth and agglomeration as a result of ion irradiation.

• OSTI ID: 22273878
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
CRYSTALLIZATION
CRYSTALS
GRAIN GROWTH
INTERFACES
ION BEAMS
IRON
IRON NITRIDES
IRON OXIDES
IRRADIATION
MAGNETIC PROPERTIES
MICROSTRUCTURE
MORPHOLOGY
NANOSTRUCTURES
PHYSICAL RADIATION EFFECTS
SILICON IONS
SUBSTRATES
SURFACES
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
VALENCE