We calculated the specific absorption rate (SAR) and relaxation time of a dilute assembly of spherical iron nanoparticles with cubic anisotropy distributed in a viscous liquid. The behavior of unit magnetization vector was investigated by the solution of stochastic Landau–Lifshitz equation. The spatial orientation of magnetic nanoparticle was determined by the set of stochastic equations for multiple particle directors. The particle viscous and magnetic magnetization reversal modes are revealed at low and sufficiently high amplitudes of alternating magnetic field, respectively. The SAR of iron nanoparticle assembly is shown to exceed significantly that of iron oxide nanoparticles with uniaxial anisotropy at the same amplitudes and frequencies of applied magnetic field. The linear response theory is shown to be valid only at small magnetic field amplitudes, H₀ ≤ 50–70 Oe.

我们计算了分布在粘性液体中的具有立方各向异性的球形铁纳米粒子的稀释组装的比吸收率 (SAR) 和弛豫时间。通过求解随机Landau-Lifshitz方程来研究单位磁化矢量的行为。磁性纳米粒子的空间取向由多粒子导向器的一组随机方程确定。粒子粘性和磁性磁化反转模式分别在交变磁场的低振幅和足够高的振幅下显示。在施加磁场的相同幅度和频率下，铁纳米颗粒组装的 SAR 显着超过具有单轴各向异性的氧化铁纳米颗粒的 SAR。H ₀  ≤ 50–70 Oe。