关键词：
磁性颗粒;非线性电导;光学非线性;非线性极化率
摘 要：
应用有效非线性电导理论,讨论了随机分布的复合磁性颗粒材料的非线性行为,得到金属颗粒复合体系的有效非线性电导率与平方电导的关系式(χe/σe2);在此基础上,导出了小颗粒在无涡流情况下系统的有效光学非线性极化率χ′e的表示式,并对结果进行了分析讨论.结果表明:在有限频率,磁性颗粒(金属)-绝缘合成系统和理想金属合成系统在逾渗极限附近χe/σe2为发散.复合介质系统非线性极化率χ′e的增强机制是:系统内粒子间相互作用对局域场增强效应的影响.该理论分析的结果与Hamanaka等的实验结果相吻合,也与Olbright的数字讨论的结论一致.
译 名：
An Analysis of Effective Nonlinear Third-Order Susceptibilities to Magnetic Granules
作 者：
ZHENG Yong-lin, GE Ze-lingDepartment of Physics, Yangtze Normal University, Chongqing 408100, China
关键词：
magnetic granule; nonlinear conductivity; optical nonlinearity; nonlinear susceptibilities
摘 要：
The article discusses the nonlinear behavior of a random composite magnetic material by the theory of the effective nonlinear conductivity. We obtain expression of the composite material about the effective nonlinear conductivity ( χe) with square conductance (σe2). Based on this, we present and analyze the exact results for the cubic nonlinear susceptibilities of granular systems in non-eddy-current cases. The results show that at finite frequencies, the relation χe/σe2 is to diverge near the percolation threshold for both a metal-insulator composite and a normal-metal-perfect-conductor composite; the physical mechanism of the enhancement of cubic nonlinear susceptibilities in granular systems is due to the influence induced by the interaction between the particles and the local field. The results of theoretical analysis are consistent with the results in the experiment of Hamanaka et al and with those of the numerical study reported in literature [7].
