Correlated Spin Canting in Ordered Core-Shell Fe3O4/MnxFe3-xOd4^ Nanoparticle Assemblies

Published

March 18, 2019

Author(s)

Y. Ijiri, Kathryn L. Krycka, I. Hunt-Isaak, H. Pan, J. Hsieh, Julie Borchers, James Jennings Rhyne, Samuel D. Oberdick, A. Abdelgawad, S. A. Majetich

Abstract

Polarization-analyzed small-angle neutron scattering methods are used to determine the spin arrangements in ordered three-dimensional assemblies of 7.4 nm diameter core-shell Fe₃O₄/Mn_xFe_3-xO₄ nanoparticles. In moderate to high magnetic fields, the assemblies display a canted magnetic structure where the canting direction is coherent from nanoparticle to nanoparticle, in contrast to the less extended, more single particle-like behavior for similar ferrite assemblies. The observed magnetic scattering is modeled by assuming that the interparticle dipolar coupling combined with Zeeman energy effects in a field leads to nanoparticle domains with preferred net spin alignments relative to pre-existing packing symmetry axes. The model qualitatively explains the observed scattering anomalies which change significantly over a range of fields and temperatures, highlighting the possibly complex structures adopted in real, dense nanoparticle systems.

Citation

Physical Review B

Volume

99

Issue

9

Pub Type

Journals

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Keywords

Small Angle Neutron Scattering, Polarization analysis, Magnetic Nanoparticles, Dipole Interactions, Long-Range Magnetic Correlations

Citation

Ijiri, Y. , Krycka, K. , Hunt-Isaak, I. , Pan, H. , Hsieh, J. , Borchers, J. , Rhyne, J. , Oberdick, S. , Abdelgawad, A. and Majetich, S. (2019), Correlated Spin Canting in Ordered Core-Shell Fe₃O₄/Mn_xFe_3-xOd4^ Nanoparticle Assemblies, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926983 (Accessed April 26, 2024)