Department of Chemical Engineering and Material Science, University of Minnesota, Minneapolis, MN, USA.
Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA.
Int J Hyperthermia. 2023;40(1):2223371. doi: 10.1080/02656736.2023.2223371.
Magnetic nanowires (MNWs) are potential candidates for heating in biomedical applications that require rapid and uniform heating rates, such as warming cryopreserved organs and hyperthermia treatment of cancer cells. Therefore, it is essential to determine which materials and geometries will provide the optimal heating using available alternating magnetic fields (AMF).
Micromagnetic simulations are used to investigate the heating ability of MNWs by predicting their hysteretic behavior. MNWs composed of iron (Fe), nickel (Ni), cobalt (Co) or permalloy (FeNi alloy, Py) with different diameters (10-200 nm) are simulated using object oriented micromagnetic framework (OOMMF).
Hysteresis loops are obtained for each simulated MNW, and the 2D/3D magnetic moment map is simulated to show the reversal mechanism. The heating ability, in terms of specific loss power (SLP), is calculated from the area of the hysteresis loop times frequency for each MNW for comparison with others.
It is estimated that a theoretical optimal heating ability of 2730 W/g can be provided by isolated Co MNWs with 50 nm diameters using a typical AMF system that can supply 72 kA/m field amplitude and 50 kHz in frequency. Generalized correlation between coercivity and size/material of MNWs is provided as a guidance for researchers to choose the most appropriate MNW as a heater for their AMF system and .
磁性纳米线（MNWs）是在需要快速和均匀加热速率的生物医学应用中加热的潜在候选者，例如冷冻保存器官的加热和癌细胞的热疗。因此，确定哪些材料和几何形状将使用可用的交变磁场（AMF）提供最佳加热效果至关重要。
使用磁各向异性微磁模拟（OOMMF）来预测 MNWs 的磁滞行为，从而研究 MNWs 的加热能力。模拟了不同直径（10-200nm）的铁（Fe）、镍（Ni）、钴（Co）或坡莫合金（FeNi 合金，Py）组成的 MNWs。
为每个模拟的 MNW 获得了磁滞回线，并模拟了 2D/3D 磁矩图以显示反转机制。通过将每个 MNW 的磁滞回线面积乘以频率来计算加热能力（以比损耗功率（SLP）表示），以便与其他 MNW 进行比较。
使用典型的 AMF 系统，估计直径为 50nm 的孤立 Co MNWs 可以提供 2730W/g 的理论最佳加热能力，该系统可以提供 72kA/m 的场振幅和 50kHz 的频率。提供了 MNWs 的矫顽力与尺寸/材料之间的一般相关性，以指导研究人员为其 AMF 系统选择最合适的 MNW 作为加热器。
