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arXiv · 2203.17014

Fundamental inequalities in the Stoner-Wohlfarth model

C. A. Iglesias·J. C. R. de Araujo·E. F. Silva·M. Gamino·M. A. Correa·F. Bohn
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Abstract

We report two fundamental inequalities in the Stoner-Wohlfarth model. Specifically, we investigate the theoretical limit for the initial magnetic susceptibility in a system described by the Stoner-Wohlfarth approach. We also find analytical solutions for the magnetization in the low-field regime and obtain the borderline value for the uniaxial anisotropy constant in such an ideal Stoner-Wohlfarth system. We go beyond and introduce a general mean-field theory for interacting Stoner-Wohlfarth-like systems, thus estimating how the initial magnetic susceptibility is affected by the dipolar and exchange interactions inside the system. By means of a simple insight from a fundamental inequality for the magnetic susceptibility of an ideal Stoner-Wohlfarth system, we show its violation is a signature of the existence of exchange interactions between nanoparticles in an interacting Stoner-Wohlfarth-like system.

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C. A. Iglesias, J. C. R. de Araujo, E. F. Silva, M. Gamino, M. A. Correa, F. Bohn. 2022-03-31. Fundamental inequalities in the Stoner-Wohlfarth model. https://doi.org/10.1103/physrevb.106.094405

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