Vékony Vilmos, Márián István G, Szabó István A
University of Debrecen, Doctoral School of Physics, 4032, Debrecen, Egyetem Tér 1, Hungary.
Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, H-4039, Debrecen, Bem tér 18/b, Hungary.
Heliyon. 2024 Sep 22;10(19):e38290. doi: 10.1016/j.heliyon.2024.e38290. eCollection 2024 Oct 15.
The behavior of magnetic nanoparticles in a time-varying magnetic field has several practical applications. One of these is hyperthermia used in the treatment of cancer. The nanoparticles injected in the tumor cells release the energy absorbed from the time dependent external magnetic field in the form of heat to its environment in a well-localized way. The aim of the research in this area is to maximize the amount of the dissipated energy. Using a combination of an oscillating and static magnetic field, this dissipated energy can be more focused in space. In this article, we investigated whether this spatial focusing is also present using a rotating and static field together. Furthermore, we investigated the effects of anisotropy and interaction between nanoparticles on this spatial focusing effect using the jump-diffusion model for Néel relaxation in both cases. This kinetic Monte Carlo (MC) method was validated and compared with the stochastic Landau-Lifshitz-Gilbert (SLLG) equation based model. We have shown that the spatial focusing effect is also present for these non-idealized experimentally realizable cases. Also, the effect of rotating magnetic field on magnetic nanoparticles was not investigated in kinetic Monte Carlo simulations before.
磁性纳米粒子在时变磁场中的行为有若干实际应用。其中之一是用于癌症治疗的热疗。注入肿瘤细胞的纳米粒子以热量的形式将从随时间变化的外部磁场吸收的能量以高度局部化的方式释放到其周围环境中。该领域的研究目标是使耗散能量最大化。通过结合振荡磁场和静态磁场，这种耗散能量可以在空间上更集中。在本文中，我们研究了同时使用旋转磁场和静态磁场时是否也存在这种空间聚焦现象。此外，在这两种情况下，我们使用用于尼尔弛豫的跳跃扩散模型研究了纳米粒子的各向异性和相互作用对这种空间聚焦效应的影响。这种动力学蒙特卡罗（MC）方法得到了验证，并与基于随机朗道 - 里夫希茨 - 吉尔伯特（SLLG）方程的模型进行了比较。我们已经表明，对于这些非理想化的、可通过实验实现的情况，空间聚焦效应也存在。此外，在动力学蒙特卡罗模拟中，之前尚未研究旋转磁场对磁性纳米粒子的影响。
