Enhanced nanocomposite susceptibility by field-alignment of superparamagnetic particles

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zambach, Mathias, Varón, Miriam, Veile, Thomas, Knaapila, Matti, Almásy, László, Plivelic, Tomás S., Johansson, Christer, Ouyang, Ziwei, Beleggia, Marco, Frandsen, Cathrine
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917375397330944
author Zambach, Mathias
Varón, Miriam
Veile, Thomas
Knaapila, Matti
Almásy, László
Plivelic, Tomás S.
Johansson, Christer
Ouyang, Ziwei
Beleggia, Marco
Frandsen, Cathrine
author_facet Zambach, Mathias
Varón, Miriam
Veile, Thomas
Knaapila, Matti
Almásy, László
Plivelic, Tomás S.
Johansson, Christer
Ouyang, Ziwei
Beleggia, Marco
Frandsen, Cathrine
contents Nanocomposites comprised of insulated magnetic single-domain particles are promising candidates for high-frequency, eddy current free, soft magnetic materials, but tend to suffer from low magnetic susceptibility ($<20$). Particle alignment has been proposed to increase nanocomposite susceptibility and reduce magnetic losses but experimental verification has been lacking. Here, magnetic nanocomposites containing 3-57 vol\% field-aligned 11$\pm$3 nm maghemite particles in a poly-vinyl matrix were investigated for potential use as high-frequency inductor core materials. The particles were aligned by a homogenous static alignment field during nanocomposite drying, fixating the particle orientation. Particle aggregation was disproved by small-angle scattering. The dependence of the alignment field strength and particle concentration on the nanocomposite's susceptibility and hysteresis losses were investigated from DC up to 922 kHz by vibrating sample magnetometry, AC-susceptibility and high-frequency hysteresis measurements. Nanocomposite susceptibility increased super-linearly with particle fraction due to weak particle interactions. Alignment of the particles increased the nanocomposite susceptibility from 21 to 50 for samples with a particle content of 57 vol\%. Hence, the synergy between particle alignment and interaction allows for a higher than expected susceptibility of nanocomposites. The results show that magnetically aligning particles in a nanocomposite reduces magnetic losses when using well-dispersed single-domain superparamagnetic nanoparticles. Measured nanocomposite susceptibility could be modelled by a combination of directional dependent Debye-models including mean-field interaction effects and partial particle alignment. Measured susceptibility of 50 is among the highest obtained for nanocomposites, making it a relevant candidate for applications in power electronics.
format Preprint
id arxiv_https___arxiv_org_abs_2603_29983
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Enhanced nanocomposite susceptibility by field-alignment of superparamagnetic particles
Zambach, Mathias
Varón, Miriam
Veile, Thomas
Knaapila, Matti
Almásy, László
Plivelic, Tomás S.
Johansson, Christer
Ouyang, Ziwei
Beleggia, Marco
Frandsen, Cathrine
Applied Physics
Mesoscale and Nanoscale Physics
Nanocomposites comprised of insulated magnetic single-domain particles are promising candidates for high-frequency, eddy current free, soft magnetic materials, but tend to suffer from low magnetic susceptibility ($<20$). Particle alignment has been proposed to increase nanocomposite susceptibility and reduce magnetic losses but experimental verification has been lacking. Here, magnetic nanocomposites containing 3-57 vol\% field-aligned 11$\pm$3 nm maghemite particles in a poly-vinyl matrix were investigated for potential use as high-frequency inductor core materials. The particles were aligned by a homogenous static alignment field during nanocomposite drying, fixating the particle orientation. Particle aggregation was disproved by small-angle scattering. The dependence of the alignment field strength and particle concentration on the nanocomposite's susceptibility and hysteresis losses were investigated from DC up to 922 kHz by vibrating sample magnetometry, AC-susceptibility and high-frequency hysteresis measurements. Nanocomposite susceptibility increased super-linearly with particle fraction due to weak particle interactions. Alignment of the particles increased the nanocomposite susceptibility from 21 to 50 for samples with a particle content of 57 vol\%. Hence, the synergy between particle alignment and interaction allows for a higher than expected susceptibility of nanocomposites. The results show that magnetically aligning particles in a nanocomposite reduces magnetic losses when using well-dispersed single-domain superparamagnetic nanoparticles. Measured nanocomposite susceptibility could be modelled by a combination of directional dependent Debye-models including mean-field interaction effects and partial particle alignment. Measured susceptibility of 50 is among the highest obtained for nanocomposites, making it a relevant candidate for applications in power electronics.
title Enhanced nanocomposite susceptibility by field-alignment of superparamagnetic particles
topic Applied Physics
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2603.29983