In the context of magnetic hyperthermia, several physical parameters are used to optimize the heat generation, and these include the nanoparticles concentration and the magnitude and frequency of the external AC magnetic field. Here, we extend our previous work by computing nonlinear contributions to the specific absorption rate, while taking into account (weak) inter-particle dipolar interactions and a DC magnetic field. In the previous work, the latter were shown to enhance the specific absorption rate in some specific geometries and setup. We find that the cubic correction to the AC susceptibility does not modify the qualitative behavior observed earlier but does bring a non-negligible quantitative change of specific absorption rate, especially at relatively high AC field intensities. Incidentally, within our approach based on the AC susceptibility, we revisit the physiological empirical criterion on the upper limit of the product of the AC magnetic field intensity H 0 and its frequency f and provide a physicist’s rationale for it.

中文翻译：

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磁性纳米粒子的比吸收率：非线性交流磁化率

在磁热疗的背景下，几个物理参数用于优化发热，其中包括纳米颗粒浓度以及外部交流磁场的幅度和频率。在这里，我们通过计算对特定吸收率的非线性贡献来扩展我们之前的工作，同时考虑（弱）粒子间偶极相互作用和直流磁场。在之前的工作中，后者被证明可以提高某些特定几何形状和设置中的比吸收率。我们发现对 AC 磁化率的三次校正不会改变先前观察到的定性行为，但确实带来了特定吸收率的不可忽略的定量变化，尤其是在相对较高的 AC 场强度下。顺便，