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Examination of the magnetism dynamics from intermixing effects in γ-Fe2O3/MnO core-shell nanoparticles

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4915096· OSTI ID:1241379
 [1];  [2];  [2];  [3];  [1]
  1. Univ. of Manitoba, Winnipeg, MB (Canada)
  2. National Tsing Hua Univ., Hsinchu (Taiwan)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
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We have examined the effects of core-shell intermixing on the dynamical magnetism of γ-Fe2O3/MnO nanoparticles. The core and shell phases were identified using x-ray diffraction, and x-ray absorption spectroscopy identified Mn ions in both octahedral and tetrahedral sites, consistent with a significant amount of substitution at the core-shell interface to form an Fe/Mn-ferrite. The dynamical response was probed by Mössbauer spectroscopy, which decouples surface and core spins, and suggested a change in the relaxation behaviour among the spin populations within γ-Fe2O3/MnO relative to the γ-Fe2O3 seed particles. Interestingly, the magnetic relaxation effects at the atomic scale, measured via Mössbauer spectroscopy, were enhanced, indicating that the addition of an MnO shell and intermixing affected the dynamical freezing process which altered the surface magnetism of the γ-Fe2O3 core. Furthermore, our results show that both the MnO shell and the interfacial intermixed layer are important in determining the core-shell nanoparticle magnetism.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE; Canada Foundation for Innovation (CFI); Natural Sciences and Engineering Research Council of Canada (NSERC)
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1241379
Alternate ID(s):
OSTI ID: 22409927
Journal Information:
Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 17 Vol. 117; ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (23)

The Iron Oxides book July 2003
The infrared dielectric properties of maghemite, ?-Fe2O3, from reflectance measurement on pressed powders journal February 1995
Synthesis of iron oxide/manganese oxide composite particles and their magnetic properties journal July 2014
Recent advances in magnetic structure determination by neutron powder diffraction journal October 1993
Magnetic order in - nanoparticles: a XMCD study journal March 2005
Distinguishing the core from the shell in MnOx/MnOy and FeOx/MnOx core/shell nanoparticles through quantitative electron energy loss spectroscopy (EELS) analysis journal January 2012
A New Nonhydrolytic Single-Precursor Approach to Surfactant-Capped Nanocrystals of Transition Metal Oxides journal December 1999
Resolving Material-Specific Structures within Fe 3 O 4 |γ-Mn 2 O 3 Core|Shell Nanoparticles Using Anomalous Small-Angle X-ray Scattering journal January 2013
Robust antiferromagnetic coupling in hard-soft bi-magnetic core/shell nanoparticles journal December 2013
Direct evidence for an interdiffused intermediate layer in bi-magnetic core–shell nanoparticles journal January 2014
Strongly exchange coupled inverse ferrimagnetic soft/hard, MnxFe3−xO4/FexMn3−xO4, core/shell heterostructured nanoparticles journal January 2012
Moment fluctuations in 7nm γ‐Fe2O3 nanoparticles probed at the atomic level using Mössbauer spectroscopy journal April 2008
Interplay between magnetism and chemical structure at spinel-spinel interfaces journal May 2012
Valence states and occupation sites in (Fe,Mn) 3 O 4 spinel oxides investigated by soft x-ray absorption spectroscopy and magnetic circular dichroism journal June 2008
The magnetic proximity effect in a ferrimagnetic Fe 3 O 4 core/ferrimagnetic γ-Mn 2 O 3 shell nanoparticle system journal December 2011
Increased surface spin stability in γ-Fe 2 O 3 nanoparticles with a Cu shell journal March 2012
Surface spin-glass freezing in interacting core–shell NiO nanoparticles journal April 2008
Exchange Striction Effects in MnO and MnS journal January 1970
Mössbauer spectra of single-domain fine particle systems described using a multiple-level relaxation model for superparamagnets journal January 2001
Direct observation of electron doping in La 0.7 Ce 0.3 MnO 3 using x-ray absorption spectroscopy journal March 2003
Stoichiometry of Fe 3 − δ O 4 ( 111 ) ultrathin films on Pt(111) journal June 2003
Modified magnetic ground state in NiMn 2 O 4 thin films journal October 2010
Magnetism of iron oxide based core-shell nanoparticles from interface mixing with enhanced spin-orbit coupling journal January 2014

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