In this paper, Fe 3 O 4 particles with different diameters are added to epoxy resin. Dielectric properties and the electrical tree growth characteristics of the specimens are tested in magnetic field. Experimental results show that magnetic field leads to higher charge carrier mobility and more serious electrical tree degradation. The addition of ferromagnetism particles with a diameter of 20 nm generates more deep traps and causes the decrease of conductivity. Moreover, nanocomposites show great inhibition effect to electrical tree whether high magnetic field is applied. Particles with a diameter of 500 nm play a role as scattering center of electrical tree and cause larger damage area. Ferromagnetism particles with a diameter of $30\ \mu\mathrm{m}$ induce local magnetic field and electric field concentration, accelerating the growth of electrical tree. Quantum chemical and electrodynamics calculation are combined to analyze the energy level distribution and the charge carrier dynamic behavior in high magnetic field. Changes in electrical tree growth result from the size effects of Fe 3 O 4 particles, including changing relative permeability, as well as acting as exciton killer, scattering center and weak points.

中文翻译：

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铁磁性粒子对环氧树脂/Fe3O4复合材料在磁场中电树生长的影响

在本文中，Fe 3 哦 4将不同直径的颗粒加入环氧树脂中。在磁场中测试样品的介电特性和电树生长特性。实验结果表明，磁场导致更高的电荷载流子迁移率和更严重的电树退化。添加直径为 20 nm 的铁磁性粒子会产生更深的陷阱并导致电导率下降。此外，无论是否施加高磁场，纳米复合材料对电树都有很大的抑制作用。直径为 500 nm 的粒子作为电树的散射中心，造成较大的损伤区域。直径为$30\ \mu\mathrm{m}$诱导局部磁场和电场集中，加速电树生长。结合量子化学和电动力学计算，分析强磁场下的能级分布和电荷载流子动力学行为。Fe 的尺寸效应导致电树生长的变化 3 哦 4 粒子，包括改变相对渗透率，以及充当激子杀手、散射中心和弱点。