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arXiv · 2506.05028

Magnetic Dissipation in Ferrofluids

Lili Vajtai·Norbert Marcel Nemes·Maria del Puerto Morales·Bence Gábor Márkus·László Forró·Ferenc Simon
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Abstract

Ferrofluids, composed of magnetic nanoparticles suspended in a non-magnetic carrier liquid, have attracted considerable attention since their discovery in the 1960s. Their combination of liquid and magnetic properties gives rise to complex behaviors and unique functionalities, enabling a wide range of technological applications. Among these is the ability of the magnetic material to be moved by and to absorb heat when exposed to an external magnetic field -- a process that can occur through various dissipation mechanisms depending on the system. A detailed understanding of these mechanisms is crucial for tailoring materials to specific applications. We provide a comprehensive overview of the theoretical principles underlying different energy dissipation processes and propose a coherent framework for their interpretation. Particular attention is devoted to describing the frequency-dependent susceptibility, which is the key parameter to describe dissipation. We demonstrate that dissipation, predicted from magnetometry-based studies, matches well with direct, frequency-dependent calorimetric results, expanding the available frequency range of the characterization. The demonstrating measurements were carried out with a dilute ferrofluid containing magnetite nanoparticles of a mean diameter of 10.6 nm.

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Lili Vajtai, Norbert Marcel Nemes, Maria del Puerto Morales, Bence Gábor Márkus, László Forró, Ferenc Simon. 2025-06-05. Magnetic Dissipation in Ferrofluids. https://arxiv.org/abs/2506.05028

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