Journal Article

FZJ-2021-04323

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Signature of antiphase boundaries in iron oxide nanoparticles

Köhler, T.FZJ* ; Feoktystov, A.FZJ* ; Petracic, O.FZJ* ; Nandakumaran, N.FZJ* ; Cervellino, A. ; Brückel, T.FZJ*

2021
Wiley-Blackwell [S.l.]

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Please use a persistent id in citations: http://hdl.handle.net/2128/29187  doi:10.1107/S1600576721010128

Abstract: Iron oxide nanoparticles find a wide variety of applications, including targeted drug delivery and hyperthermia in advanced cancer treatment methods. An important property of these particles is their maximum net magnetization, which has been repeatedly reported to be drastically lower than the bulk reference value. Previous studies have shown that planar lattice defects known as antiphase boundaries (APBs) have an important influence on the particle magnetization. The influence of APBs on the atomic spin structure of nanoparticles with the γ-Fe2O3 composition is examined via Monte Carlo simulations, explicitly considering dipole–dipole interactions between the magnetic moments that have previously only been approximated. For a single APB passing through the particle centre, a reduction in the magnetization of 3.9% (for 9 nm particles) to 7.9% (for 5 nm particles) is found in saturation fields of 1.5 T compared with a particle without this defect. Additionally, on the basis of Debye scattering equation simulations, the influence of APBs on X-ray powder diffraction patterns is shown. The Fourier transform of the APB peak profile is developed to be used in a whole powder pattern modelling approach to determine the presence of APBs and quantify them by fits to powder diffraction patterns. This is demonstrated on experimental data, where it could be shown that the number of APBs is related to the observed reduction in magnetization.

Keyword(s): Magnetic Materials (1st) ; Magnetism (2nd) ; Materials Science (2nd) ; Medicine (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Streumethoden (PGI-4)
3. JARA-FIT (JARA-FIT)
4. Streumethoden (JCNS-2)

Research Program(s):

1. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)
2. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2021

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Wiley ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; PubMed Central ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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