FeCoB—SiO2纳米磁性颗粒膜有效磁导率计算与模拟

用带Gilbert损耗项的Landau-Lifshitz 方程和Bruggeman有效媒质理论对Fe40Co40B20-SiO2纳米磁性颗粒膜的有效磁导率进行计算模拟,采用的模型是由磁性颗粒与非磁性介质组成的面心立方结构体系.模拟结果表明,磁谱曲线的变化趋势与实验数据一致,薄膜有效磁导率的实部和虚部都随着磁性颗粒的体积分数增大而增大.当磁性颗粒的体积分数在0.3到0.5之间变化时,磁导率的变化并不明显,而当磁性颗粒的体积分数在0.5到0.6之间变化时,磁导率的变化非常明显,这说明复合薄膜在磁性颗粒体积分数为0.5到0.6之间出现了逾渗阈值.

Calculation and Simulation of Frequency Spectra of Effective Permeability of FeCoB-SiO2 Nano-granular Magnetic Films

An analytic calculation of effective permeability frequency spectra of the Fe40Co40B20-SiO2 nano-granular thin film was presented, using the LLG equation and Bruggeman effective medium theory. The nano-granular thin film model studied consists of magnetic nano-granules and SiO2 with a FCC structure. Results show that the curve of the frequency spectra agrees well with the experimental results. Both the real and imaginary part of the complex permeability increase with the volume fraction of magnetic granule. The permeability changes slowly in the volume fraction of magnetic granule of 0.3 to 0.5, but the permeability changes markedly and the percolation threshold appears when the volume fraction changes between 0.5 to 0.6.