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arXiv · 2610.02977

Optimizing the magnetic hyperthermia efficiency from the structural dependence of dipolar interactions in magnetic nanoparticles assemblies

Abdelhamid Morjane·François Vernay·Vincent Russier
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Abstract

Magnetic hyperthermia, based on the conversion of the magnetic energy of magnetic nanoparticles (MNP) under an alternating external field into heat, presents a great interest, especially because of important applications such as promising advances in cancer treatment. The underlying frequency-dependent response of the MNP assembly under the excitation field depends on the first hand on the individual properties of the MNP such as their size, shape and magnetocrystalline anisotropy and on the other hand on collective properties generated by interactions between MNP. Due to the long-range dipolar component of the latter, the first consequence is the so-called demagnetizing effects, making the response dependent on the external sample shape. This is the reason for studying the properties of MNP in assemblies of anisotropic external shapes such as films, chains, or elongated aggregates. In the present work, using a recently developed Time Quantified Monte Carlo (TQMC) framework for dynamic simulations, we focus more precisely on the importance of the local structure in such anisotropic aggregates to the dipolar interactions contribution of the response to the external field. Here the local structure is understood as both the location of the nanoparticles and the distribution of their easy axes. We show that the latter must be determined in a self-consistent way starting with the equilibrium structure of a ferrofluid modeled as the dipolar hard sphere fluid.

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Abdelhamid Morjane, François Vernay, Vincent Russier. 2026-10-02. Optimizing the magnetic hyperthermia efficiency from the structural dependence of dipolar interactions in magnetic nanoparticles assemblies. https://arxiv.org/abs/2610.02977

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