Reference : Dipolar-coupled moment correlations in clusters of magnetic nanoparticles |
Scientific journals : Article | |||
Physical, chemical, mathematical & earth Sciences : Physics | |||
Physics and Materials Science | |||
http://hdl.handle.net/10993/38322 | |||
Dipolar-coupled moment correlations in clusters of magnetic nanoparticles | |
English | |
Bender, Philipp Florian ![]() | |
Wetterskog, E. [> >] | |
Honecker, Dirk ![]() | |
Fock, J. [> >] | |
Frandsen, C. [> >] | |
Moerland, C. [> >] | |
Bogart, L. K. [> >] | |
Posth, O. [> >] | |
Szczerba, W. [> >] | |
Gavilán, H. [> >] | |
Costo, R. [> >] | |
Fernández-Díaz, M. T. [> >] | |
González-Alonso, D. [> >] | |
Fernández Barquín, L. [> >] | |
Johansson, C. [> >] | |
2018 | |
Physical Review. B, Condensed Matter | |
American Physical Society | |
98 | |
224420 | |
Yes (verified by ORBilu) | |
International | |
0163-1829 | |
1095-3795 | |
New York | |
MD | |
[en] Here, we resolve the nature of the moment coupling between 10-nm dimercaptosuccinic acid–coated magnetic
<br />nanoparticles. The individual iron oxide cores were composed of >95% maghemite and agglomerated to <br />clusters. At room temperature the ensemble behaved as a superparamagnet according to Mössbauer and magnetization <br />measurements, however, with clear signs of dipolar interactions. Analysis of temperature-dependent <br />ac susceptibility data in the superparamagnetic regime indicates a tendency for dipolar-coupled anticorrelations <br />of the core moments within the clusters. To resolve the directional correlations between the particle moments <br />we performed polarized small-angle neutron scattering and determined the magnetic spin-flip cross section <br />of the powder in low magnetic field at 300 K. We extract the underlying magnetic correlation function of <br />the magnetization vector field by an indirect Fourier transform of the cross section. The correlation function <br />suggests nonstochastic preferential alignment between neighboring moments despite thermal fluctuations, with <br />anticorrelations clearly dominating for next-nearest moments. These tendencies are confirmed by Monte Carlo <br />simulations of such core clusters. | |
http://hdl.handle.net/10993/38322 | |
also: http://hdl.handle.net/10993/38326 ; http://hdl.handle.net/10993/41165 | |
10.1103/PhysRevB.98.224420 | |
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.98.224420 | |
FP7 ; 604448 - NANOMAG - Nanometrology Standardization Methods for Magnetic Nanoparticles |
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