Abstract The heat dissipated by magnetic nanoparticles may be used as a heat source for hyperthermic treatment of cancer and it can be estimated based on the magnetic susceptibility when an alternating current (AC) magnetic field is applied. Here, the frequency dependence of the magnetization of magnetic nanoparticles is measured for different AC fields. This is used to examine the AC susceptibility of linear and nonlinear magnetization responses. Two methods were used to evaluate the AC susceptibility based on measured magnetization properties. The first used the static susceptibility and phase delay associated with magnetic relaxation, and the second used the area under the AC magnetization curve to derive the imaginary part of the susceptibility. When the field intensity was low, the estimated AC susceptibilities were comparable. However, when the field intensity was high, the first method predicted a lower value because it did not consider the nonlinearity of the magnetization response. To optimize the material and the applied field conditions for hyperthermia it is important to understand the difference between the two methods. The intrinsic loss power and specific loss power of the magnetic nanoparticles were also evaluated. A liquid sample and a solid sample with an oriented easy axis provided high heat dissipation.

中文翻译：

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使用其线性和非线性响应的交流磁化率评估磁性纳米粒子的功率损耗

摘要 磁性纳米粒子散发的热量可用作癌症热疗的热源，并且可以根据施加交流（AC）磁场时的磁化率来估计。在这里，针对不同的交流场测量了磁性纳米粒子磁化的频率依赖性。这用于检查线性和非线性磁化响应的交流磁化率。基于测量的磁化特性，使用两种方法来评估交流磁化率。第一个使用与磁弛豫相关的静态磁化率和相位延迟，第二个使用 AC 磁化曲线下的面积来推导出磁化率的虚部。当场强低时，估计的交流磁化率是可比的。然而，当场强较高时，第一种方法预测的值较低，因为它没有考虑磁化响应的非线性。为了优化热疗的材料和应用场条件，了解两种方法之间的区别非常重要。还评估了磁性纳米颗粒的固有损耗功率和比损耗功率。具有定向易轴的液体样品和固体样品提供高散热。还评估了磁性纳米颗粒的固有损耗功率和比损耗功率。具有定向易轴的液体样品和固体样品提供高散热。还评估了磁性纳米颗粒的固有损耗功率和比损耗功率。具有定向易轴的液体样品和固体样品提供高散热。