Poster (Invited)

FZJ-2026-02192

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Magnetic relaxation and structural characterization of single-core FeOxnanoparticle dispersions in solvents of varying viscosity

Thuruthiyil Jose, A.FZJ* ; Ehlert, S.FZJ* ; Feoktystov, A.FZJ* ; Stadler, A.FZJ* ; Dulle, M.FZJ* ; Petracic, O.FZJ*

2026

Abstract: We have investigated the structural and magnetic properties of monodispersesingle-core iron-oxide nanoparticles dispersed in solvents of systematically variedviscosity. The particles were synthesized via thermal decomposition. Magneticmeasurements were performed using SQUID magnetometry, employingzero-field-cooled (ZFC) and field-cooled (FC) curves to probe changes in blockingbehavior and relaxation dynamics. To examine the influence of the solventenvironment on particle stability, SAXS measurements were carried out. We observeclear viscosity-dependent shifts in the nanoparticle solvent system, reflectingthe gradual emergence of Brownian relaxation as solvent mobility increases.The observed viscosity and phase-dependent magnetic signatures demonstratehow solvent dynamics can be used to tune and separate Neel and Brownian relaxation.

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Contributing Institute(s):

1. Streumethoden (JCNS-2)
2. JARA-FIT (JARA-FIT)
3. Neutronenstreuung (JCNS-1)
4. JCNS-4 (JCNS-4)

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)

Appears in the scientific report 2026

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